At least 24 people are reported to have been killed in suicide bomb blasts in the north-east Nigerian town of Mubi.
The explosions happened in and around a mosque as Muslims were preparing for afternoon prayers.
Police in Adamawa state said they suspect the Islamist group Boko Haram of being behind the attacks.
Boko Haram has waged a campaign of violence to try to create an Islamic state in the north of Nigeria since 2009.
The violence has killed about 20,000 people and displaced more than two million.
State police commissioner Abdullahi Yerima said the first blast took place at the mosque at about 13:00 (12:00 GMT) and a second bomber detonated a device nearby as worshippers fled.
He said more than a dozen people were injured.
Mubi has suffered regular attacks by Boko Haram. Last November more than 50 people were killed when suspected militants detonated a suicide bomb inside a mosque in the same town.