Police removed tents set up by protesters near the Bahrain Financial Harbour centre, at a short distance from Pearl Square, where anti regime demonstrators have been staging a sit in since February 14.

There were "eight injuries among policemen. all were transferred to hospital," the ministry said on its Twitter page after announcing that police had fired tear gas to disperse some 350 protesters.

The ministry urged protesters to "remain in the (Pearl) roundabout for their safety," insisting the operation was aimed at reopening King Faisal Highway next to the financial centre.

Activists said they would stage a sit in at Financial Harbour at noon (0900 GMT) on Sunday, aiming to block the entrance with a human chain.

Demonstrators at Pearl Square said anti riot police were gathering at a bridge over the square.

Security forces had avoided the area since February 17 after six protesters were shot dead. A seventh died later of his wounds.

Hardline anti regime activists have been intensifying their protests outside Pearl Square, staging demonstrations at the government headquarters and royal palaces.

On Friday, police fired tear gas to disperse demonstrators who marched towards a royal palace to prevent clashes with armed loyalists.

Protests in Shia majority Bahrain, which is ruled by a Sunni dynasty, broke out after popular uprisings in Egypt and Tunisia toppled those countries' long time autocratic rulers.

The main opposition groups have stopped short of demanding the toppling of the king, insisting on major reforms, but hardliners have been vocal in calling for the end of monarchy.