Shots rang out Wednesday as Bahraini troops backed with armoured vehicles began clearing Manama's financial district of illegal road blocks, as handfuls of protesters offered little resistance.

Military helicopters circled overhead as the troops escorted a bulldozer into the Financial Harbour business complex, the centre of a regional finance hub that hosts major international banks and multinational corporations.

An AFP reporter at the scene said shots were fired in the side streets but there appeared to be no resistance from anti-government demonstrators who had seized the business district on Sunday, paralysing the economy.

Banks have been closed for days and the stock market moved premises for safety reasons on Monday.