Several attackers were killed on Thursday after a convoy transporting Cameroon's Defence Minister Joseph Beti Assomo was ambushed while heading for a visit to a military post seven kms (four miles) from the town of Kumba in the restive South-West region, state radio reports.

The convoy had 30 vehicles, including an armour-plated vehicle that was carrying the minister and six generals, a reporter with state daily the Cameroon Tribune told news agency AFP.

Gregoire Djarmaila, who was injured in the attack by flying glass, said that they encountered a roadblock and their car was riddled by gunfire.

The military escort returned fire, enabling the convoy to reach the military post, he said.

"But no sooner had we left the post than we were attacked again. This time, they looked more numerous and determined... (they fired) on all the vehicles in the convoy."

"Our good luck was that they were using home-made hunting guns" rather than military weapons, adding that he experienced "40 minutes of hell," Djarmaila said.

Separatists in Cameroon's two mainly English-speaking areas - the North-West and South-West regions - have been demanding independence saying they are being discriminated against by the French-speaking majority.