Gesture aims to win popular backing for offensive; Nigerian warplanes hitting militant camps in north.

Officials blame attack on local ethnic cult Ombatse.

The new arms, and the willingness of extremists to use them, highlight the increasing instability in the north.

Latest in a string of increasingly bloody attacks in Africa's most populous nation.

Two Nigerian policemen and five attackers were killed in a midnight raid on a police station by suspected members of Boko Haram.

Fighting between soldiers and Islamic extremists in northeast Nigeria killed at least 187 people, the worst single incident of violence in the region in three years.

No confirmation of reports from a local official that 185 people had been killed in the violence.