Facing a potentially violent ouster, one of the extremist groups, Ansar Dine, which has occupied key cities such as Timbuktu for seven months.

Preparations are accelerating for an intervention in Islamist-occupied northern Mali as West African leaders prepare to adopt a military blueprint this weekend before seeking UN approval.

Algeria, with its superior military capabilities and its 1,400-kilometre (875-mile) border with Mali, is seen as key to any military operation but it favours a negotiated solution instead.

The UN special envoy for the Sahel, Romano Prodi, said Thursday "Military intervention as a fait accompli was "a last resort"