MANAMA, Bahrain (AP) - 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.
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.
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.