MANAMA, Bahrain — Soldiers fired tear gas and shot heavy weapons into the air today as thousands of protest marchers defied a government ban and streamed toward the landmark square that has been the symbolic center of the uprising against the Gulf nation’s leaders.

Hospital officials said at least 20 people were injured, some seriously. Ambulance sirens were heard throughout central Manama a day after riot police swept through the protest encampment in Pearl Square, killing at least five people and injuring more than 230.

An Associated Press cameraman saw army units shooting anti-craft weapons above the protesters in apparent warning shots and attempts to drive them back from security cordons about 200 yards from the square.

The clash came just hours after funeral mourners and worshippers at today’s prayers called for the toppling of the Western-allied monarchy in the tiny island nation, which is home to the U.S. Navy’s 5th Fleet.