Police and emergency officials say two suicide bombers killed at least 15 students while they were in lectures at a government college in Nigeria's northern city of Kano.

Kano state police commissioner Aderenle Shinaba said Wednesday another 34 students suffered various injuries.

Spokesman Sani Datti of the Nigerian Emergency Management Agency said the bombers also died.

Officials blamed Islamic extremists from Boko Haram. The group is blamed for five suicide bombings carried out in one week in July in Kano. It is also blamed for a string of car bombs and suicide bombings that have killed scores of people across their stronghold in northeast Nigeria as well as in Abuja, Nigeria's capital in the center of the country, and a failed attempt in Lagos, the commercial capital in the southwest.