The explosion took place at a mosque in Mubi, Adamawa State, Northeast Nigeria, according to the local media.
The blast happened in the afternoon while worshippers were holding Zuhr prayer.
The explosion was set off by a teenager using a suicide vest, according to witnesses.
Around 20 people were killed in blasts in the Northeast Nigerian town of Mubi, the police commissioner of Adamawa state said.
Earlier, more than 50 armed people reportedly invaded the Mbadwen village in the Benue State and burned it down, leaving at least 35 people killed.
Nigeria has been facing the insurgency of the Boko Haram, who vouched for allegiance to the Daesh (ISIL or ISIS) terror group, since 2009.
The group staged a number of terror attacks, including the 2011 bombing of a UN office in the country’s capital of Abuja which killed 21 people.