Hundreds of protestors have clashed with riot police in the town of Tizi Ouzou, in Algeria's Berber-dominated region of Kabylie.

The BBC's Mohamed Arezki Himeur in Algiers says trouble broke out when the police stopped a demonstration which had been called to demand the release of dozens of protestors arrested in March.

The group of elders which has been leading the protests has warned the authorities that it will force government officials out of Kabylie if the detainees are not released by Sunday.

The region has been engulfed in violence for more than a year, following the death in police custody of a teenager.

'Siege'

Thursday's riot began when the security forces stopped a march organised by Kabylie's Coordination of Traditional Tribes, who has spearheaded the protest movement.

Police used tear gas to disperse the demonstrators, who threw stones and petrol bombs.

Police have been using tear gas against Berber demonstrators

The police also deployed anti-riot vehicles and erected a series of roadblocks around Tizi Ouzou to prevent residents of nearby villages from joining the march.

The city looked as if under siege as most shops, offices and banks had shut down following a call for a general strike.

The protestors are demanding the withdrawal of the gendarmes, the full recognition of the Berber language and improved living conditions.

They have warned that they will drive government officials out of Kabylie if the militants jailed four months ago are not freed.

Some of them have been on hunger strike for a few days.

Local residents feel that the detainees are being kept as hostages by the security forces to coerce them into negotiations with the government.