Forty prisoners have escaped from a jail in the northern Nigerian town of Damaturu after it was stormed by a group of armed men, police say.

Yobe state police commissioner Patrick Egbuniwe said his men were overpowered by at least 40 attackers at the prison.

The past few months have seen several jail breaks in northern Nigeria, some but not all of which have been admitted by the Islamist group Boko Haram.

There were no suspected Boko Haram members in the jail, Mr Egbuniwe said.

The attackers ent...