Three bombs exploded outside a northern Nigerian mosque on Friday while gunman shot at people attempting to escape the building, Nigerian state-run broadcaster NTA reported. At least 92 people were killed and 126 injured in one of Nigeria's bloodiest terrorist attacks.

The gruesome blast occurred when worshippers had gathered for Friday prayers inside the Central Mosque in the northern city of Kano, northern Nigeria's largest city, where Islamist militant group Boko Haram has a significant presence and has fought an anti-government campaign to institute Sharia, or Islamic law, The Telegraph reported.

While two explosives blasted in the courtyard of the mosque, a third one went off some distance away, eyewitnesses said. As crowds started fleeing outside, gunman opened fire with automatic weapons.

"These people have bombed the mosque. I am face to face with people screaming," Chijjani Usman, one of the worshippers, told Reuters.

"Two bombs exploded, one after the other, in the premises of the Grand Mosque seconds after the prayers had started," eyewitness Aminu Abdullahi said.

"A third one went off in a nearby road. The blasts were followed by gunshots by the police to scare off potential attacks," Abdullahi told Agence France Presse.

Although no group has claimed responsibility yet, the incident bore the hallmarks of Boko Haram, a radical Islamist movement linked to al-Qaeda which has killed thousands of people in northern Nigeria and forced over a million to flee their homes, according to CNN.

Specifically, the target of the assault could have been the Emir of Kano, Mohammad Sanusi II, who is often known to attend prayers at the Central Mosque. But the outspoken opponent of Boko Haram is believed to have been in Saudi Arabia on Friday.

"These people, when they attack towns, they kill boys and enslave girls. People must stand resolute." Sansui urged citizens of Kano earlier this month to "acquire what they can to defend themselves" and "not wait for soldiers to protect them."

Meanwhile, previous attacks attributed to the terrorist group in Kano include a wave of bombings that killed 180 people in one day in 2012 and a suicide bombing that killed six people, including three police officers, at a gas station this month.

With almost ten million people, Kano is the biggest city in northern Nigeria and the sixth largest in the Muslim world.

Boko Haram, which means "Western education is a sin," is still believed to be holding more than 200 girls it abducted in April from a school in Chibok, Borno state.