Nigerian authorities are cracking down on the abuse of children branded as witches after a British investigation into the practice.

A man calling himself "the bishop", who said he had killed more than 100 people "possessed" by the devil, has been arrested.

"The bishop" was filmed performing "exorcisms" of children held captive at a camp in the Niger delta. He exploited superstitions about witchcraft to abuse children and extort money from their families. The children have since been freed.

Following the investigation by Channel 4's Dispatches, the governor of Akwa Ibom state, Godswill Akpabio, said he would "destroy and demolish" every church engaged in such practices.