Bahrain's opposition accused the kingdom's Sunni authorities of killing three protesters in a violent raid on Wednesday on a peaceful pro-democracy camp that sparked Shiite outrage across the region.
Hundreds of riot police backed by tanks and helicopters fired shotguns and tear gas canisters early morning at demonstrators in Pearl Square, clearing the symbolic heart of the uprising in the strategic Gulf kingdom.
"We now have three martyrs," Khalil Marzouk, deputy head of the Al-Wefaq movement and a member of parliament, told AFP, adding that the situation was "catastrophic" with hospitals closed off and Shiite villages surrounded.
The violence came a day after King Hamad, boosted by the arrival in the tiny island state of armed forces from Saudi Arabia and the United Arab Emirates, declared a three-month state of emergency in a bid to quell the protests.
Police arrived in tanks and buses before moving in on the mainly Shiite Muslim demonstrators, who have been camped out in the square for a month to press for a constitutional monarchy and an end to repression.