Nigerian rescue officials say two female bombers have killed at least 22 worshippers in an attack on a mosque.
The attack took place on the outskirts of the northeastern city of Maiduguri - the birthplace of the Boko Haram armed group.
Abdul Mohammed of the State Emergency Management Agency told The Associated Press news agency that another 17 people were wounded in the explosions early on Wednesday.
Coordinator Abba Aji of the civilian self-defence Vigilante Group says one bomber blew up inside the mosque and the second outside as survivors tried to flee.
Aji says the mosque is in Umarari on the outskirts of the city that is now the command centre of the Nigerian military's war against Boko Haram Islamic insurgents.
Several bombers have exploded themselves in recent months at roadblocks into the city manned by the military and vigilantes.