MANAMA, Bahrain – Soldiers and riot police 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 neighbors in the Persian Gulf fearful for their own rule and the spread of Shiite Iran’s influence.

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, who blocked 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 hot spot. 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.

Officials in the hospital said they took in 107 injured from Wednesday’s violence.

King Hamad bin Isa Al Khalifa’s announcement of three months of 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 Obama called King Abdullah of Saudi Arabia and Al Khalifa to express deep concern over the violence. White House spokesman Jay Carney said Obama stressed the need for “maximum restraint.”