At least 15 people were killed as Nigeria's Bayero University at Kano was rocked by several explosions on Sunday morning disrupting Christian prayers, the BBC reported. It said its reporter had seen six bodies and local police fear the toll could be higher.
"There was a huge explosion at the open air theatre close to the entrance of the old site of the university during a church service by Christian students," AFP quoted a source as saying.
Not less than three explosions have occurred in the area and gunfire was also heard by residents.
The locality was cordoned off as the military took control of the entire region.
The BBC, citing Reuters, quoted Mohammed Suleiman, a history lecturer at the university, as saying: "For over 30 minutes a series of bomb explosions and gun shots took over the old campus, around the academic blocks."
The blasts hit the old section of the campus at Bayero University. Official spokesperson Abubakar Jibril for the country's National Emergency Management Agency confirmed three explosions combined with gunfire.
"There were casualties, but I don't have exact figures. Some are so injured and have been rushed to local hospitals," Military spokesperson Lt Iweha Ikedechi was quoted by the Associated Press as saying.
So far, no group has claimed responsibility for the attack although the Islamist militant Boko Haram group is widely believed to be active in the region.
The same group had carried out a deadly bomb attack in January 2012 which killed more than 150 people. The group allegedly has ties with al-Qaida-linked terrorist organisations in Africa.
Nigeria has the largest population in Africa and is the largest oil producer. Seven people were killed in their suicide car bombing attack at newspaper buildings last Thursday.