(Al Jazeera) – At least four people were killed and 15 others injured in a suicide bomb attack on a university campus in northeast Nigeria, police said. The blast happened on Monday at a mosque in the staff quarters area of the University of Maiduguri, and is thought to have been carried out by a teenage girl, a local resident and a lecturer told AFP news agency. There was no immediate claim of responsibility but suspicion will likely fall on the armed group Boko Haram, which has repeatedly used young women and girls as human bombs.