Soldiers and riot police in Bahrain overran a protesters' camp, imposed a 12-hour curfew and choked off movement nationwide Wednesday. Witnesses described helicopters firing on homes in a hunt for Shiites and attacking doctors treating the wounded, while the government called the demonstrators "outlaws" for demanding an end to the monarchy.
The nation that once led the Middle East in entrepreneurial openness went into lockdown, its government propped up by troops from Sunni Gulf neighbors fearful for their own rule and the spread of Shiite Iran's influence.
The unrest that began last month increasingly looks like a sectarian showdown. The country's Sunni leaders are desperate to hold power, and majority Shiites want more rights and an end to the monarchy.
Wednesday's assault began in Pearl Square, the center of the uprising inspired by Arab revolts in Egypt and Tunisia. But the violence that left at least five people dead on Wednesday did not stop in the capital.
Doctors at the country's main hospital said their facility was taken over by security forces, blocking physicians from either leaving or treating the wounded on site.
"There are many people injured, but we can't bring them to the hospital because of the travel restrictions, and doctors can't come to us," said Ali Marsouk, a resident of the Shiite village of Sitra, who said helicopters fired on homes in a three-hour attack.
Rania Ali, another resident, said police were charging after Shiites as they sought shelter.
"I saw them chasing Shiites like they were hunting," said Ali, a Sunni whose husband is Shiite.
The Salmaniya hospital complex has become a political hotspot. The mostly Shiite personnel are seen by authorities as possible protest sympathizers. The staff claim they must treat all who need care.
There have been moments of open anger. As overwhelmed teams treated the injured from Tuesday's clashes, many broke out in calls to topple the monarchy.
"We are under siege," said Nihad el-Shirawi, an intensive care doctor who said she had been working for 48 hours. "We cannot leave, and those on-call cannot come in."
Officials in the hospital said they took in 107 injured from Wednesday's violence. Nine were in critical condition, officials in the hospital said on condition of anonymity because they were not authorized to speak to reporters.
The Salmaniya hospital also treated 322 people injured in clashes across the kingdom on Tuesday, the official said.
The king's announcement of a three-month emergency rule and the crackdown on Pearl Square sent a message that authorities will strike back in the strategic island nation, which hosts the U.S. Navy's 5th Fleet.
President Barack Obama called King Abdullah of Saudi Arabia and King Hamad bin Isa Al Khalifa of Bahrain to express deep concern over the violence. White House spokesman Jay Carney said Obama stressed the need for "maximum restraint."
Security forces barred journalists and others from moving freely. A 4 p.m to 4 a.m. curfew was imposed in most of the country.
U.S. Secretary of State Hillary Rodham Clinton said the introduction of Gulf forces was "the wrong track."
"There is no security answer to this, and the sooner they get back to the negotiating table and start trying to answer the legitimate needs of the people, the sooner there can be a resolution that will be in the best interests of everyone," she told CBS News.
Witnesses said at least two protesters were killed when the square was stormed. Officials at Ibn Nafees Hospital said a third protester died later. The witnesses spoke on condition of anonymity because of fear of reprisals.
A government statement said the only deaths during the raid were two policemen who were "repeatedly run over by three vehicles containing protesters."
The government did not say whether the offensive included soldiers from other Gulf nations _ a Saudi-led force that has grown to nearly 1,000.
State TV showed military vehicles flying Bahrain's red-and-white flag as security officials moved through the wreckage of the encampment, set up at the base of a monument to the country's history as a pearl diving center.
During the attack, protesters fled into side streets and security forces blocked main roads into Manama. Mobile phones were apparently jammed during the height of the attack and Internet service remained at a crawl.
Hamid Zuher, a 32-year-old protester who slept at the square, said riot police first moved in on foot.
"They fired tear gas and then opened fire," Zuher said. "We lifted our arms and started saying 'Peaceful, Peaceful.' Then we had to run away."
The government said security forces came under attack from about 250 "saboteurs" hurling gasoline bombs and responded with tear gas. It denied live ammunition was used.
In Shiite villages, people went to mosques and held protest prayers. Others lit fires in anger. Clashes were reported in other mostly Shiite areas, where traffic was controlled by military forces in an apparent attempt to prevent gatherings or a surge of people toward the capital.
The government offers hints of a growing propaganda campaign. A statement said forces conducted an operation to "cleanse" Pearl Square and later state TV called the demonstrators "saboteurs" and "outlaws."
A senior opposition leader, Abdul Jalil Khalil, believes the messages seek to bring sectarian civil war.
"And what do they think, that spreading this hate will break our will?" Khalil said. "Until now, we were defiant at Pearl Square. Now we are defiant in every village and town."
Bahrain's sectarian clash is increasingly viewed as an extension of the region's rivalries between the Gulf Arab leaders and Iran. Washington, too, is being pulled deeply into the Bahrain's conflict because of its naval base _ the Pentagon's main Gulf counterweight to Iran.
Iranian President Mahmoud Ahmadinejad on Wednesday denounced the crackdown and the presence of the Saudi-led force.
"How is it possible to stop waves of humanity with military force?" Ahmadinejad said.
Before the rise of Dubai and Qatar's capital Doha, the business center of the Gulf was in Bahrain. The tiny nation successfully marketed itself in the 1990s as a Western-friendly outpost for banking and financial services as a way to offset its relatively meager oil revenue. Its skyline _ now dwarfed by Dubai _ was once a symbol of the Gulf's emergence on the world stage.
The unrest has already given a stinging blow: the cancellation of the Formula 1 season-opening Bahrain Grand Prix this month. The race is a major tourism draw and the highlight of Bahrain's international calendar.
Associated Press writers Brian Murphy in Dubai, United Arab Emirates; Adam Schreck in Abu Dhabi; Hamid Ahmed in Baghdad, and Ali Akbar Dareini in Tehran, Iran, contributed to this report.