Tony Mitchell / AP
In this image from video riot police firing tear gas and wielding clubs storm an anti-government protesters' camp in Pearl Square, Manama before dawn on Feb. 17.
Hamad I Mohammed / Reuters
Tents at Pearl Square are cleared of protesters, several hours after riot police attacked in the early hours of Feb. 17.
Mazen Mahdi / EPA
Medics attend to a victim of clashes between demonstrators and police arriving at Salmaniya Medical Complex, Manama, Bahrain, early on Feb. 17.
Hassan Ammar / AP
An anti-government demonstrator shows a cell phone picture of a wounded man who she said was injured during the riot police attack on Pearl Square early on Feb. 17.
Armed patrols prowled neighborhoods in Manama, Bahrain and tanks appeared in the streets for the first time Thursday after riot police with tear gas and clubs drove protesters from a main square where they had demanded sweeping political change in this tiny kingdom. Medical officials said four people were killed.
Police cars with flashing blue lights encircled Pearl Square, the site of anti-government rallies since Monday. Barbed wire was set up on streets leading to the square, where police cleaned up flattened protest tents and trampled banners. The Interior Ministry declared the protest camp "illegal" and warned Bahrainis to stay off the streets.