Calm was slowly returning to the streets of Bahrain, a day after forces drove protesters off the streets and cleared a camp that had become a symbol of their demand for more rights.

Pearl roundabout was a scene of devastation. Some tattered tents remained on the grass as diggers uprooted palm trees that surrounded the pearl statue where activists camping.

Parts of central Manama are under the full control of security forces. Tanks and armored personnel carriers outfitted with machine guns watched over strategic intersections. Soldiers manned checkpoints and searched cars. Agents in civilian clothes patrolled wearing green vests and masks.

Troops were only allowing residents in and a long line of cars was backed up behind a checkpoint, waving through drivers heading to work in the financial district, where the protesters had tried to extend their sit-in early this week.

About 1,500 troops from Saudi Arabia and the United Arab Emirates are in Bahrain as part of a Gulf task force to help the kingdom's authorities.

Nearly all supermarkets were closed and traffic was light. Very few people were walking the streets in the centre of the capital.

The military on Wednesday banned all protests and imposed a curfew from 4 pm to 4 am across a large swathe of Manama.

Bank branches and coffee shops in the commercial district prepared to open. "It's back to normal, I can see traffic on King Faisal Highway. We drove all the way to work," said a bank employee.

Several international bank branches and other businesses in Bahrain remained shut. HSBC said it reopened just one of its four branches. Standard Chartered reopened two of its seven branches. Both banks shut all their offices Wednesday.

Bahrain's stock exchange reopened. It was up 1.3 percent by midday.