BAIDA, Libya — As rebellion crept closer to the capital and defections of military officers multiplied, Col. Muammar el-Qaddafi called on thousands of mercenaries and irregular security forces on Wednesday to defend his bastion in Tripoli, in what residents said was a desperate and dangerous turn in the week-old uprising.       

Distrustful of even his own generals, Colonel Qaddafi has for years quietly built up this ruthless and loyal force. It is made up of special brigades headed by his sons, segments of the military loyal to his native tribe and its allies, and legions of African mercenaries he has helped train and equip. Many are believed to have fought elsewhere, in places like Sudan, but he has now called them back.       

Witnesses said thousands of members of this irregular army were massing on roads to the capital, Tripoli, where one resident described scenes evocative of anarchic Somalia: clusters of heavily armed men in mismatched uniforms clutching machine guns and willing to carry out orders to kill Libyans that other police and military units, and even fighter pilots, have refused.       

Some residents of Tripoli said they took the gathering army as a sign that the uprising might be entering a decisive stage, with Colonel Qaddafi fortifying his main stronghold in the capital and protesters there gearing up for their first organized demonstration after days of spontaneous rioting and bloody crackdowns.       

The fall of other cities to rebels on Wednesday, including Misurata, 130 miles east of the capital, left Colonel Qaddafi more embattled — and his opponents emboldened.       

“A message comes to every mobile phone about a general protest on Friday in Tripoli,” one resident of Tripoli said. Colonel Qaddafi’s menacing speech to the country on Tuesday — when he vowed to hunt down opponents “house by house” — increased their determination “100 percent,” the resident said.       

Dozens of checkpoints operated by a combination of foreign mercenaries and plainclothes militiamen lined the road west of Tripoli for the first time, witnesses said, requiring not only the presentation of official papers but also displays of flag-waving, fist-pumping enthusiasm for Colonel Qaddafi, who has long fashioned himself as a pan-African icon.       

“You are trying to convince them you are a loyalist,” one resident said, “and the second they realize that you are not, you are done for.”       

The overall death toll so far has been impossible to determine. Human rights groups say they have confirmed about 300 deaths, though witnesses suggested the number was far larger. On Wednesday, Franco Frattini, the foreign minister of Italy — the former colonial power with longstanding ties — said that nationwide more than 1,000 people were probably dead in the strife.       

Egyptian officials said Wednesday that nearly 30,000 people — mostly Egyptians working in Libya — had fled across their border. People fleeing west into Tunisia said the rebellion was now taking off far from its origins just a week ago in the eastern city of Benghazi, Libya’s second largest city, which fell over the weekend.       

There were reports for the first time of protests in the southern city of Sabha, considered a Qaddafi stronghold.       

On Wednesday, in addition to the northwestern city of Misurata, protesters claimed victory in nearby Zawai, where local army units are said to have joined them. Some said there had been intense fighting in the past few nights in the town of Sabratha, home of an important Roman archaeological site 50 miles west of Tripoli, where witnesses on Wednesday reported a heavy deployment of machine-gun toting foreign mercenaries and Qaddafi loyalists known as revolutionary committees.       

“The revolutionary committees are trying to kill everyone who is against Qaddafi,” said a doctor fleeing Sabratha, declining to give his name for fear of reprisals if he returned.       

But amid spreading rebellion and growing defections by top officials, diplomats and segments of the regular army, Colonel Qaddafi’s preparations for a defense of Tripoli also reframed the question of who might still be enforcing his rule. It is a puzzle that military analysts say reflects the singular  character of the society he has shaped — half tribal, half police state —  for the past 41 years.       

“It is all shadow and mirrors and probably a great deal of corruption as well,” said Paul Sullivan, a professor at Georgetown who has studied the Libyan military.       

Colonel Qaddafi, who took power in a military coup, has always kept the Libyan military too weak and divided to do the same thing to him. About half its relatively small 50,000-member army is made up of poorly trained and unreliable conscripts, according to the Center for Strategic and International Studies.       

Many of its battalions are organized along tribal lines, ensuring their loyalty to their own clan rather than to top military commanders — a pattern evident in the defection of portions of the army to help protesters take the eastern city of Benghazi.       

Colonel Qaddafi’s own clan dominates the air force and the upper level of army officers, and they are  believed to have remained loyal to him, in part because his clan has the most to lose from his ouster.       

Other clans, like the large Warfalla tribe, have complained that they have been shut out of the top ranks, Professor Sullivan noted, which may help explain why they were among the first to turn on Colonel Qaddafi.       

Untrusting of his officers, Colonel Qaddafi built up an elaborate paramilitary force — accompanied by special segments of the regular army that report primarily to his family. It is designed to check the army and in part to subdue his own population. At the top of that structure is his roughly 3,000-member revolutionary guard corps, which mainly guards him personally.       

Then there are the militia units controlled by Colonel Qaddafi’s seven sons. A cable from the United States Embassy in Libya released by WikiLeaks described his son Khamis’s private battalion as the best equipped in the Libyan Army.       

His brother Sa’ad has reportedly used his private battalion to help him secure business deals. And a third brother, Muatassim, is Colonel Qaddafi’s national security adviser. In 2008 he asked for $2.8 billion to pay for a battalion of his own, to keep up with his brothers.       

But perhaps the most significant force that Colonel Qaddafi has deployed against the current insurrection is one believed to consist of about 2,500 mercenaries from countries like Chad, Sudan and Niger that he calls his Islamic Pan African Brigade.       

Colonel Qaddafi began recruiting for his force years ago as part of a scheme to bring the African nations around Libya into a common union, and the mercenaries he trained are believed to have returned to Sudan and other bloody conflicts around Africa. But from the accounts of many witnesses Colonel Qaddafi is believed to have recalled them — and perhaps others — to help suppress the uprising.       

Since the Libyan military withdrew from the eastern border, Egyptian officials said, tens of thousands of Egyptians — many of whom had worked in Libya’s oil-propelled economy — have fled back to Egypt. About 4,200 crossed over on Sunday, a similar number on Monday, and about 20,000 on Tuesday, when border security collapsed.       

The Egyptian authorities said the migrants brought the bodies of three people killed in the crackdown on Benghazi, five people wounded by bullets and 14 others who were taken to a hospital with serious injuries. Many complained that they had been attacked and robbed by the mercenaries, officials said.       

Mustafa Said Ahmed, 26-year-old accountant who had worked in Benghazi, said in an interview that he saw 11 people killed by the mercenaries in “a massacre” after the noon prayer last Friday.       

The country’s long-serving interior minister, Gen. Abdel Fattah Younes al-Abidi, said Wednesday that he had decided to resign after the people of Benghazi were shot down with machine guns.       

In an interview with CNN, he said he had argued against Colonel Qaddafi’s intention to use airplanes to bomb that city, the nation’s second largest, warning that it would kill thousands. State media, however, claimed he had been kidnapped by “gangs.”       

The justice minister has already resigned for similar reasons. Two Libyan bombers diverted to Malta rather than bomb civilians, and on Wednesday a Libyan newspaper reported that a third Libyan military pilot had downed his bomber in the eastern province rather than carry out a mission to bomb Benghazi.       

After nightfall on Wednesday, witnesses reported sporadic bursts of gunfire around Tripoli neighborhoods. But they said the streets seemed eerily deserted. Green Square, which had been a rallying point for pro-Qaddafi forces, had only a few hundred left in it. And the state television headquarters, which had been heavily guarded, was left almost unattended.       

Elsewhere, there were signs that Colonel Qaddafi’s forces were refortifying. For the first time, witnesses said, at least four army tanks had rolled into the streets of the capital.       

MOSCOW — It once seemed as if Nikita Tikhonov was positioning himself to join this country’s political elite: he attended the prestigious Moscow State University, founded a right-wing political magazine called The Russian Way and worked as a campaign aide for a parliamentary candidate.       

A self-declared patriot with a passion for Russian history, Mr. Tikhonov refused to smoke or drink alcohol, insisting that a blend of temperance and civic engagement might help revive his country.       

Now, Mr. Tikhonov is on trial for murder.       

Prosecutors contend that his right-wing intellectual pursuits mutated into nationalistic hatred that led him to kill a prominent human rights lawyer and a young journalist two years ago. Mr. Tikhonov initially confessed to the crime, though he now says he is innocent. Testimony in his trial, which includes his wife as a co-defendant, is scheduled to begin on Monday.       

Whatever his original path, Mr. Tikhonov has now come to embody the increasing radicalization of Russia’s nationalist movement, his true nature, perhaps, revealed more in the tattoos covering his body, including one on his left shoulder of a cross ringed with swastikas.       

Like Mr. Tikhonov, 30, many of the extreme nationalists are young, educated and middle class. They are angry at myriad enemies, real and perceived, and are earning a worsening reputation for widespread political violence.       

One of the most widely publicized cases came in December, in the wake of the fatal shooting an ethnic Russian soccer fan here by a man from Russia’s North Caucasus region. Thousands of young people began an extended riot close to Red Square, chanting “Russia for Russians” and racial slurs. They threw rocks at police officers, and then scattered. Later, groups of ethnic Russian men and some women attacked non-Slavic minorities on side streets and subways. Several people were reported killed.       

Ethnic Russians make up about 80 percent of Russia’s 142 million people, sharing the country with more than 100  ethnic groups, many of which make up Russia’s large Muslim community. Russia also has the largest immigrant population in the world after the United States, numbering as many as 10 million, mostly from former Soviet republics in the South Caucasus and Central Asia.       

Nationalists have taken responsibility for kidnappings, beheadings and a 2006 bombing that killed 10 at a Moscow market operated mostly by immigrants. At least 37 people were killed and more than 300 injured in xenophobic attacks in 2010, according to the Sova Center, a Moscow-based organization that tracks such violence. Many more cases go unreported.       

Nationalists have also singled out those considered sympathetic to ethnic minorities or opposed to right-wing ideas and deeds. They have killed several members of an anti-fascist group called Anti-Fa, which arose in response to growing xenophobic violence. In the past year, nationalists have been linked to the murders of several police officers and a judge.       

Aleksandr Belov, a nationalist leader who once worked with Mr. Tikhonov, blamed the government for the recent violence, saying Russia’s leaders ignored the interests of ethnic Russians, favoring well-organized and influential diasporas while squeezing nationalists out of power. This, he said, has prompted some to take up arms to stave off perceived threats against Russia’s culture and traditions.       

“It is becoming an armed struggle,” Mr. Belov said. “You can call such people terrorists, but there is another name: these are partisans who are fighting a war of liberation.”  

Copyright.2011. The New York Times Company. All Rights Reserved     

Based on testimony from Mr. Tikhonov’s friends, prosecutors contend that he considered himself a part of this struggle.       

“In conversations, he expressed intolerance toward immigrants in Russia and non-Slavs, and expressed racist ideas,” a friend, Sergei Yerzunov, also an avowed nationalist, told investigators, according to court documents. “He said that the main goal, not only of his activities, but of the whole nationalist movement, should be the struggle against ideological opponents.”       

Mr. Tikhonov is accused of killing two such enemies. One, Stanislav Markelov, a lawyer, for years pressed the authorities to have perpetrators of hate crimes brought up on charges, leading to the imprisonment of several. The other, Anastasia Baburova, a freelance journalist with Novaya Gazeta, the country’s leading opposition newspaper, wrote about nationalists.       

They were shot to death together at close range in January 2009 in a brazen, daylight attack just a short walk from the Kremlin. Prosecutors have charged Mr. Tikhonov’s common-law wife, Yevgenia Khasis, with aiding the attack, and she is also now on trial.       

The killings were met with satisfaction if not outright jubilation in some nationalist circles. One nationalist carried Champagne to a makeshift memorial a day after the shootings, placing the bottle amid the flowers in the still-red snow.       

Investigators say that Mr. Markelov was the intended target. His investigation into the 2006 stabbing death of an anti-fascist activist led to Mr. Tikhonov being named a suspect. Though Mr. Tikhonov denied involvement — and prosecutors later dropped the charges against him — he fled.       

For three years he lay low in a rented Moscow apartment. Using an alias and fake documents, he left Russia for a time, possibly living in Ukraine, friends and relatives said. He used pay phones to make sporadic calls, though he avoided revealing his whereabouts.       

His lawyer, Aleksandr Vasilyev, said Mr. Tikhonov made a living selling weapons on the black market. The police discovered an arsenal stashed in his apartment upon his arrest in November 2009; among the weapons confiscated was the Browning pistol used to shoot Mr. Markelov and Ms. Baburova.       

Despite the evidence against Mr. Tikhonov, his family and friends contend that he is innocent, describing him as a convenient suspect because of his earlier ties to Mr. Markelov, but ultimately the victim of a government crackdown on nationalists.       

Though nationalists tend to portray themselves as oppressed, the government’s treatment of them has been more ambivalent. While Russia’s leaders have vehemently condemned xenophobic violence, they also have at times seemed to try to co-opt nationalist sentiment.       

The Kremlin has allowed right-wing groups to hold rallies in Moscow, where participants have made Nazi salutes, even as it blocks protests by the liberal opposition.       

Perhaps under different circumstances, Mr. Tikhonov, with his college degree and passion for history, might have become a conservative politician or joined the group of right-wing  commentators who have become a force in Western Europe.       

“I tried to raise him as a patriot,” said his father, Aleksandr Tikhonov. “He always said it was necessary to revive the nation, to take pride in your nation and take pride in your people and your ancestors.”  

Copyright. 2011. The New York Times Company. All Rights Reserved     

You may think the only people capable of snooping on your Internet activity are government intelligence agents or possibly a talented teenage hacker holed up in his parents’ basement. But  some simple software lets just about anyone sitting next to you at your local coffee shop watch you browse the Web and even assume your identity online.       

“Like it or not, we are now living in a cyberpunk novel,” said Darren Kitchen, a systems administrator for an aerospace company in Richmond, Calif., and the host of Hak5, a video podcast about computer hacking and security. “When people find out how trivial and easy it is to see and even modify what you do online, they are shocked.”       

Until recently, only determined and knowledgeable hackers with fancy tools and lots of time on their hands could spy while you used your laptop or smartphone at Wi-Fi hot spots. But a free program called Firesheep, released in October, has made it simple to see what other users of an unsecured Wi-Fi network are doing and then log on as them at the sites they visited.       

Without issuing any warnings of the possible threat, Web site administrators have since been scrambling to provide added protections.       

“I released Firesheep to show that a core and widespread issue in Web site security is being ignored,” said Eric Butler, a freelance software developer in Seattle who created the program. “It points out the lack of end-to-end encryption.”       

What he means is that while the password you initially enter on Web sites like Facebook, Twitter, Flickr, Amazon, eBay and The New York Times is encrypted, the Web browser’s cookie, a bit of code that  that identifies your computer, your settings on the site or other private information, is often not encrypted. Firesheep grabs that cookie, allowing nosy or malicious users to, in essence, be you on the site and have full access to your account.       

More than a million people have downloaded the program in the last three months (including this reporter, who is not exactly a computer genius). And  it is easy to use.       

The only sites that are safe from snoopers are those that employ the cryptographic protocol transport layer security or its predecessor, secure sockets layer, throughout your session. PayPal and many banks do this, but a startling number of sites that people trust to safeguard their privacy do not. You know you are shielded from prying eyes if a little lock appears in the corner of your browser or the Web address starts with “https” rather than “http.”       

“The usual reason Web sites give for not encrypting all communication is that it will slow down the site and would be a huge engineering expense,” said Chris Palmer, technology director at the Electronic Frontier Foundation, an electronic rights advocacy group based in San Francisco. “Yes, there are operational hurdles, but they are solvable.”       

Indeed, Gmail made end-to-end encryption its default mode in January 2010. Facebook began to offer the same protection as an opt-in security feature last month, though it is so far available only to a small percentage of users and has limitations. For example, it doesn’t work with many third-party applications.       

“It’s worth noting that Facebook took this step, but it’s too early to congratulate them,” said Mr. Butler, who is frustrated that “https” is not the site’s default setting. “Most people aren’t going to know about it or won’t think it’s important or won’t want to use it when they find out that it disables major applications.”       

Joe Sullivan, chief security officer at Facebook, said the company was engaged in a “deliberative rollout process,” to access and address any unforeseen difficulties. “We hope to have it available for all users in the next several weeks,” he said, adding that the company was also working to address problems with third-party applications and to make “https” the default setting.       

Many Web sites offer some support for encryption via “https,” but they make it difficult to use. To address these problems, the Electronic Frontier Foundation in collaboration with the Tor Project, another group concerned with Internet privacy, released in June an add-on to the browser Firefox, called Https Everywhere. The extension, which can be downloaded at  eff.org/https-everywhere, makes “https” the stubbornly unchangeable default on all sites that support it.       

Since not all Web sites have “https” capability, Bill Pennington, chief strategy officer with the Web site risk management firm  WhiteHat Security in Santa Clara, Calif., said: “I tell people that if you’re doing things with sensitive data, don’t do it at a Wi-Fi hot spot. Do it at home.”       

But home wireless networks may not be all that safe either, because of free and widely available Wi-Fi cracking programs like Gerix WiFi Cracker,  Aircrack-ng   and Wifite.  The programs work by faking legitimate user activity to collect a series of so-called weak keys or clues to the password. The process is wholly automated, said Mr. Kitchen at Hak5, allowing even techno-ignoramuses to recover a wireless router’s password in a matter of seconds. “I’ve yet to find a WEP-protected network not susceptible to this kind of attack,” Mr. Kitchen said.       

A WEP-encrypted password (for wired equivalent privacy) is not as strong as a WPA (or Wi-Fi protected access) password, so it’s best to use a WPA password instead. Even so, hackers can use the same free software programs to get on WPA password-protected networks as well. It just takes much longer (think weeks) and more computer expertise.       

Using such programs along with high-powered Wi-Fi antennas that cost less than $90, hackers can pull in signals from  home networks two to three miles away. There are also some computerized cracking devices with built-in antennas on the market, like WifiRobin ($156). But experts said they were not as fast or effective as the latest free cracking programs, because the devices worked only on WEP-protected networks.       

To protect yourself, changing the Service Set Identifier or SSID of your wireless network from the default name of your router (like Linksys or Netgear) to something less predictable helps, as does choosing a lengthy and complicated alphanumeric password.       

Setting up a virtual private network, or V.P.N., which encrypts all communications you transmit wirelessly whether on your home network or at a hot spot, is even more secure. The data looks like gibberish to a snooper as it travels from your computer to a secure server before it is blasted onto the Internet.       

Popular V.P.N. providers include VyperVPN, HotSpotVPN   and LogMeIn Hamachi.   Some are free; others are as much as $18 a month, depending on how much data is encrypted. Free versions tend to encrypt only Web activity and not e-mail exchanges.       

However, Mr. Palmer at the Electronic Frontier Foundation blames poorly designed Web sites, not vulnerable Wi-Fi connections, for security lapses. “Many popular sites were not designed for security from the beginning, and now we are suffering the consequences,” he said. “People need to demand ‘https’ so Web sites will do the painful integration work that needs to be done.”  

Copyright. 2011. The New York Times Company. All Rtghts Reserved     

MANAMA, Bahrain — Government forces opened fire on hundreds of mourners marching toward Pearl Square on Friday, sending people running away in panic amid the boom of concussion grenades. But even as the people fled, at least one helicopter sprayed fire on them and a witness reported seeing mourners crumpling to the ground.       

It was not immediately clear what type of ammunition the forces were firing, but some witnesses reported fire from automatic weapons and the crowd was screaming “live fire, live fire.”  At a nearby hospital, witnesses reported seeing people with very serious injuries and gaping wounds, at least some of them caused by rubber bullets that appeared to have been fired at close range.       

Even as ambulances rushed to rescue people, forces fired on medics loading the wounded into their vehicles. That only added to the chaos, with people pitching in to evacuate the wounded by car and doctors at a nearby hospital saying the delays in casualties reaching them made it impossible to get a reasonable count of the dead and wounded.       

A Western official said at least one person had died in the mayhem surrounding the square, and reports said at least 50 had been wounded. The official quoted a witness as saying that those shooting were in the military, not the police, indicating a hardening of the government’s stance against those trying to stage a popular revolt.       

Thousands of people gathered at the hospital, offering blood for the wounded, and doctors said they had to work as “volunteers” because the government had issued orders against helping protesters.       

The mourners who defied a government ban to march on Pearl Square were mostly young men who had been part of a funeral procession for a protester killed in an earlier crackdown by the police.       

Minutes after the first shots were fired, forces in a helicopter that had been shooting at the crowds opened fire at a Western reporter and videographer who were filming a sequence on the latest violence. Two young men who had been in the march said some of the fire came from snipers.       

The crown prince, Sheik Salman bin Hamad al-Khalifa, went on Bahrain TV to call for calm, saying, “Today is the time to sit down and hold a dialogue, not to fight,” Reuters reported.       

The violence came a day after both President Obama and Secretary of State Hillary Rodham Clinton urged the leaders of the country, a longtime ally, to show restraint. President Obama reiterated that message on Friday and condemned the violence in Bahrain, Libya and Yemen.       

“The United States condemns the use of violence by governments against peaceful protesters in those countries and wherever else it may occur,” Mr. Obama said. “We express our condolences to the family and friends of those who have been killed during the demonstrations.”       

The president, who also spoke of the right of assembly as a “universal” right, made the remarks in a statement read to reporters traveling with him on a domestic trip on Air Force One.       

At least seven people had died in clampdowns in Bahrain before Friday’s violence.       

The chaos  has left  the Obama administration in the uncomfortable position of dealing with a strategic Arab ally locked in a showdown with its people.       

The protests in Bahrain started Monday, inspired by the overthrow of autocratic governments in  Egypt and Tunisia. The Bahraini government initially cracked down hard, then backed off after at least two deaths and complaints from the United States.       

But since Thursday morning, security forces have shown little patience with the protesters, first firing on demonstrators sleeping in Pearl Square early Thursday morning, killing at least five, and then shooting today at those who gathered to mark an earlier death.       

The violence appeared to be transforming the demands of the protesters, who early on were calling for a switch from an absolute monarchy to a constitutional one. On Thursday, the opposition withdrew from the Parliament and demanded that the government step down. And on Friday, the mourners were  chanting slogans like “death to Khalifa,” referring to King Hamad bin Isa al-Khalifa.       

The protests here, while trying to mimic those in Egypt and Tunisia, add a dangerous new element: religious division. The king and the ruling elite of Bahrain are Sunni, while the majority of the population are Shiites, who have been leading the demonstrations and demanding not only more freedom but equality.       

The king is distrustful enough of his Shiite subjects that many of his soldiers and police officers are foreigners hired by the government.       

The events on Friday began at a mourning ceremony at a cemetery attended by tens of thousands of people. Afterward, the crowd began to march peacefully, but when they reached an intersection of a road that would lead toward Pearl Square, some people became visibly nervous and headed in the other direction. About 1,000 people turned toward the square.       

Although the government had issued a strict warning against protests, there were no signs that forces were waiting in the square. But when the marchers approached, shots began to ring out, sending them fleeing.       

The mourning ceremony was one of at least two held on Friday. The other, a funeral in the village of Sitra, south of Manama, drew a  crowd of thousands  who accompanied the coffins of Ali Mansour Ahmed Khudair, 53, and Mahmoud Makki Abutaki, 22, both killed by  shotgun fire  on Thursday.       

The coffins were carried on the roofs of two cars as a man with a loudspeaker   led  the crowd in its chants from the  bed of a pickup truck, alternating between calls to the faithful  — “There is no God but God” — with political messages such as, “We need constitutional reform for freedom.”       

In the sun-scorched, sandy cemetery with its crumbling white headstones, the bodies were laid to rest on their sides so that they faced  the Muslim holy city of Mecca in Saudi Arabia. “Have you seen what they have done to us?” said Aayat Mandeel, 29, a computer technician. “Killing people for what? To keep their positions?”       

After the burials, the crowds moved off to a major mosque for noon prayers on the Muslim holy day, an occasion that has provided a focus  for protests elsewhere in the region. But it was not clear whether religious leaders would urge them to continue their demonstrations.       

For the Obama administration, the violence in this tiny Persian Gulf State  was the Egypt scenario in miniature, a struggle to avert broader instability and protect its interests — Bahrain is the base of the Navy’s Fifth Fleet — while voicing support for the democratic aspiration of the protesters.       

The United States has said it strongly opposed the use of violence. Secretary of State Hillary Rodham Clinton called Bahrain’s foreign minister on Thursday morning to convey “our deep concern about the actions of the security forces,” she said. President Obama did not publicly address the Thursday crackdown, but his press secretary, Jay Carney, said that the White House was urging Bahrain to use restraint in responding to “peaceful protests.”       

In some ways, the administration’s calculations are even more complicated here, given Bahrain’s proximity to Saudi Arabia, another Sunni kingdom of vital importance to Washington, and because of the sectarian nature of the flare-up here.       

This has broader regional implications, experts and officials said, since Saudi Arabia has a significant Shiite minority in its eastern, oil-producing districts and the Shiite government in Iran would like to extend its influence over this nearby island kingdom. Shiite political figures in Bahrain deny that their goal is to institute an Islamic theocracy like that in Iran.       

For those who were in the traffic circle known as Pearl Square on Thursday when the police opened fire without warning on thousands who were sleeping there, it was a day of shock and disbelief. Many of the hundreds taken to the hospital were wounded by shotgun blasts, doctors said, their bodies speckled with pellets or bruised by rubber bullets or police clubs.       

In the morning, there were three bodies already stretched out on metal tables in the morgue at Salmaniya Medical Complex: Mr.  Khudair, dead, with 91 pellets pulled from his chest and side; Isa Abd Hassan, 55, dead, his head split in half; Mr. Abutaki,  dead, with 200 pellets of birdshot pulled from his chest and arms.       

Doctors said that at least two others had died and that several patients were in critical condition with serious wounds. Muhammad al-Maskati, of the Bahrain Youth Society for Human Rights, said he had received at least 20 calls from frantic parents searching for young children.       

A surgeon, who asked not to be identified for fear of reprisals, said that for hours on Thursday the Health Ministry prevented ambulances even from going to the scene to aid victims. The doctor said that in the early morning, when the assault was still under way, police officers beat a paramedic and a doctor and refused to allow medical staff to attend to the wounded. News agencies in Bahrain reported that the health minister, Faisal al-Hamar, had resigned after doctors staged a demonstration to protest his order barring ambulances from going to the square.       

In the bloodstained morgue, Ahmed Abutaki, 29, held his younger brother’s cold hand, tearfully recalling the last time they spoke Wednesday night. “He said, ‘This is my chance, to have a say, so that maybe our country will do something for us,’” he recalled of his brother’s decision to camp out in the circle. “My country did do something; it killed him.”       

There was collective anxiety as Friday approached and people waited to see whether the opposition would challenge the government’s edict to stay off the streets. The government had made it clear that it would not tolerate more dissent, saying  it would use “every strict measure and deterrent necessary to preserve security and general order.” Both sides said they would not back down.       

“You will find members of Al Wefaq willing to be killed, as our people have been killed,” said Khalil Ebrahim al-Marzooq, one of 18 opposition party members to announce Thursday that they had resigned their seats. “We will stand behind the people until the complete fulfillment of our demands.”       

Arab leaders have been badly shaken in recent days, with entrenched leaders in Egypt and Tunisia ousted by popular uprisings and with demonstrations flaring around the region. And now as the public’s sense of empowerment has spread, the call to change has reached into this kingdom. That has raised anxiety in Saudi Arabia, which is connected to Bahrain by a bridge, and Kuwait, as well, and officials from the Gulf Cooperation Council met here to discuss how to handle the crisis.       

After the meeting — and before Friday’s clampdown —  the council issued a statement supporting Bahrain’s handling of the protests. It also suggested that outsiders might have fomented them, in a clear effort to suggest Iranian interference.       

“The council stressed that it will not allow any external interference in the kingdom’s affairs,” said the statement, carried on Bahrain’s state news agency, “emphasizing that breaching security is a violation of the stability of all the council’s member countries.”       

“The Saudis are worried about any Shia surge,” said Christopher R. Hill, who retired last year as United States ambassador to Iraq, where he navigated tensions between Sunnis and Shiites. “To see the Shia challenging the royal family will be of great concern to them.”       

Still, Mr. Hill said there was little evidence that Arab Shiites in Bahrain would trade their king for Iranian rulers.       

Bahrain’s king and his family have long been American allies in efforts to fight terrorism and push back the regional influence of Iran. In diplomatic cables made public by WikiLeaks, he urged American officials to take military action to disable Iran’s nuclear program.       

While Bahrain has arrested lawyers and human rights activists over the last two years, it had taken modest steps to open up the society in the eight years before that, according to Human Rights Watch. King Hamad allowed municipal and legislative elections last fall, for which he was praised by Mrs. Clinton during a visit to Bahrain in December.       

In the streets, however, people were not focused on geopolitics or American perceptions of progress. They were voicing demands for democracy, rule of law and social justice.