MAIDUGURI, Nigeria: A radical sect which has claimed responsibility for Christmas Eve bombings of Nigerian churches is believed to be behind the killing of three more people at a hospital, police said Wednesday. The three victims were killed Tuesday when men fired shots in a teaching hospital in the northeastern city of Maiduguri. “An investigation has already commenced but I can tell you that we believe the killings must have been carried out by the Boko Haram since it was their mode of operations,” a police public relations officer said.