(BBC) – Witnesses say some are now being used to terrorise other captives, and are even carrying out killings themselves. The testimony cannot be verified but Amnesty International says other girls kidnapped by Boko Haram have been forced to fight. Boko Haram has killed some 5,500 civilians in Nigeria since 2014. Two-hundred-and-nineteen schoolgirls from Chibok, are still missing, more than a year after they were kidnapped from their school in northern Nigeria. Many of those seized are Christians.