At least 118 inmates have escaped from a Nigerian prison, after gunmen bombed their way inside and killed a guard during a shootout.

The prison is located in the central town of Koton-Karifi, about 120 kilometers southwest of the capital, Abuja. Police say gunmen stormed into the facility Wednesday night.

Witnesses said around 20 gunmen on motorcycles rode up to the prison, fired at guards and then set off a bomb outside the main gate. They said the gunmen specifically freed members belonging to the radical Islamic sect Boko Haram, while the others escaped during the unrest.

There was no immediate claim of responsibility for the attack and police said Thursday they were still trying to determine who carried it out.

Also Wednesday, Nigerian authorities said that an ex-soldier is wanted in connection with the Christmas Day bombing of a church in Abuja that killed more than 30 people.

The suspect, Habibu Bama, was reported to be an accomplice of Kabiru Sokoto, who was recaptured earlier this month after initially escaping custody with the help of Boko Haram.

The group is blamed for hundreds of deaths in bombings and shootings over the past 18 months, mostly in northern Nigeria. Much about the group remains unknown, but it is believed to want wider implementation of sharia, or Islamic law.