Bahrain's army says it will take all steps to ensure security as tanks roll into central areas of the capital.

Bahrain's army said on Thursday it will take all measures necessary to ensure security and is ordering people to avoid central areas of the Gulf Arab kingdom's capital.

Police in the Gulf island kingdom of Bahrain attacked demonstrators camped out in the capital on Thursday, killing three.

The aim of the attack—to stifle pro-democracy protests inspired by similar movements across the Middle East.

Police fired buckshot and teargas as they moved on Pearl Square in Manama overnight, putting to flight some 2,000 people, including women and children, who had spent three days there hoping to emulate the successful protest camp on Cairo's Tahrir Square.

At Pearl Square, abandoned tents, blankets and rubbish were scattered about, the smell of teargas wafting through the air as tanks, APC's and soldiers poured into the area.

Heavy earth moving equipment has been brought in to help clear the debris