Jihadists have killed five aid workers abducted in restive northeast Nigeria last month, humanitarian group Action Against Hunger said Wednesday. "It is with profound grief that we confirm the assassination of Ishaku Yakubu, Action Against Hunger staff member from Monguno, and four other aid workers who were taken hostage by a non-state armed group in Borno State, northeast Nigeria, on June 8," the French-based aid organisation said in a statement. del/dl