The attack also left two distinguished professors dead, they include Professor Jerome Ayodele, a professor of Analytical Chemistry and Andrew Leo of Library Science department.
Explosions and gunfire rocked Bayero University in the northern city of Kano, with witnesses reporting that two church services were targeted as they were being held on campus.
One of the services was being held outdoors, while the second was inside a building, but with an overflow audience outside, witnesses said.
Officials were unable to confirm casualty figures, but an AFP correspondent counted six bullet-riddled bodies near one of the two sites.
At least another dozen bodies could be seen on a roadside by the university, but the exact number was unclear.
Musical instruments and half-eaten meals could be seen at the site of one of the services.
An army spokesman confirmed the attack but could not provide a casualty toll. Lieutenant Iweha Ikedichi told AFP that it appeared the attackers used bombs and gunfire in the assault.
Witnesses said the attackers arrived in a car and two motorcycles, opening fire and throwing homemade bombs, causing a stampede. They said worshippers were gunned down as they sought to flee.
“They first attacked the open-air service outside the faculty of medicine,” one witness said. “They threw in explosives and fired shots, causing a stampede among worshippers. They now pursued them, shooting them with guns. … They also attacked another service at the sporting complex.”
A witness who said he was at the sporting complex at the time of the attack reported hearing gunshots outside while they were praying.
“Then there was pandemonium,” he said, adding that he later saw two men outside shooting indiscriminately.
A crowd of people later gathered at a Kano hospital waiting to hear news about friends or family.
There was no immediate claim of responsibility, although the attack was similar to others carried out by the Islamist group Boko Haram.