Abdullahi Yerima, police commissioner in Adamawa state, said a suicide bomber struck at the mosque at around 01:00 p.m. (1200 GMT) and a second bomber detonated a device some 200 metres (220 yards) away as worshippers fled.
Ezra Sakawa, chief medical director of Mubi general hospital, said about 56 were injured.
The blasts in the town of Mubi bore the hallmarks of Islamist militant group Boko Haram, which has waged an insurgency in Africa’s most populous country since 2009 and often deploys suicide bombers in crowded places.
The jihadist group on Thursday (April 26) carried out an attack in Maiduguri, capital of neighbouring Borno state, that killed four people. More than 30,000 people have been killed in the insurgency, which has also forced some two million to flee their homes.