The replacement of Nigeria's police chief comes amid growing insecurity across Nigeria with various armed groups unleashing violence.

This includes armed gangs that kidnap people for ransom, the Boko Haram insurgency, as well as clashes between farmers and herders in parts of the country.

There has also been renewed agitation by Biafra separatists in the south-east of the country.

On Monday more than 1,800 prisoners escaped after a group of men armed with guns, rocket-propelled grenades and other explosive devices attacked a prison and a police facility in the city of Owerri.

The fleeing inmates have yet to be recaptured.