Riot police firing tear gas and wielding clubs stormed a landmark square occupied by anti-government protesters in Bahrain before dawn Feb 17, driving out demonstrators and destroying a makeshift encampment that had become the hub for demands to bring sweeping political changes to the kingdom.

The main opposition group Al Wefaq said at least two people were killed in the assault on Pearl Square, which was littered with flattened tents, trampled banners and broken glass. There was no official word on deaths or injuries, but hospitals treated dozens of people with serious gaping wounds, broken bones and respiratory problems from the tear gas.

Hours after police retook control of the plaza, the tiny island nation was in lockdown mode. Tanks and armored personnel carriers were seen in some areas - the first sign of military involvement in the crisis. Police checkpoints were set up along main roadways and armed patrols moved through neighborhoods in an apparent attempt to thwart any mass gatherings.

Barbed wire was put up around Pearl Square and a message from the Interior Ministry declared the protest camp "illegal." The air still carried the smell of tear gas more than four hours after the assault, the Associated Press reported.