Eight people were killed and 20 injured by a bomb that tore through the grounds of the School of Hygiene Monday in the Nigerian city of Kano.
Police say they have detained a suspect in the blast.
Kano has experienced previous attacks blamed on the Boko Haram Islamist militants. It is near three northeastern states that are under a state of emergency because of the terrorist group.
The insurgents still hold more than 200 schoolgirls they kidnapped two months ago.
Boko Haram opposes Western education and medicine, and seek to establish an Islamist state. Thousands of people have been killed by the militants during the past five years, or in government efforts to suppress them.