Eket - The nine-year-old boy lay on a bloodstained hospital sheet crawling with ants, staring blindly at the wall.

His family pastor had accused him of being a witch, and his father then tried to force acid down his throat as an exorcism. It spilled as he struggled, burning away his face and eyes. The emaciated boy barely had strength left to whisper the name of the church that had denounced him, Mount Zion Lighthouse.

A month later, he died.

Nwanaokwo Edet was one of an increasing number of children in Africa accused of witchcraft by pastors and then tortured or killed, often by family members. Pastors were involved in half of 200 cases of "witch children" reviewed by the AP, and 13 churches were named in the case files.Some of the churches involved are renegade local branches of international franchises. Their parishioners take literally the Biblical exhortation, "Thou shalt not suffer a witch to live."

Campaigners against the practice say around 15,000 children have been accused in two of Nigeria's 36 states over the past decade and around 1,000 have been murdered.