(LAGOS, Nigeria)— The U.N. Children’s Fund says it has negotiated the release of 876 children detained at a Nigerian army barracks that holds people suspected of helping the Boko Haram extremist group. West Africa director Manuel Fontaine says the agency fears more children are at least temporarily detained. He spoke Friday following a visit to Maiduguri, the northeastern city that is home to the army’s Giwa Barracks. The Associated Press has documented the deaths of thousands of detainees there.