“PRIMEMINISTER 1970-2011, 41 YEARENOUGH.”

The protester’s message written in English on the large sign was clear: after four decades in power, it was time for a new leader.

The long-standing prime minister remains in place, despite the hundreds – one report said thousands – of Shi’ite demonstrators outside his office.

They also called for thousands of naturalised Sunnis to be expelled from the small Gulf state.

The protesters accuse the authorities of aggravating discrimination against Shi’ites by bringing in Sunnis from abroad and giving them jobs in the security forces.

The king has made concessions, but two weeks after the protests began there has been no formal dialogue between government and opposition.

Friday saw the first sectarian violence between Sunnis and Shi’ites as a local dispute in central Bahrain escalated.

Calm was later restored but there was a tense stand-off between riot police and groups of Shi’ites.

Other anti-government protests passed off without incident, continuing a pattern set when the authorities started to allow demonstrations.