At least eight people have been killed by a female suicide bomber at a mosque in north-eastern Nigeria.
The bomber was being chased by local security workers in Maiduguri and ran into the middle of worshippers, according to a spokesman for a civilian self-defence force.
At least 13 people were wounded in the explosion and the mosque collapsed in the blast.
The Nigeria-based Boko Haram extremist group often targets Maiduguri, where its eight-year insurgency began.
"There were two girls that wanted to attack the mosque but one of them got stuck in barbed wire in the ditch dug near the area, but the second one escaped and began to run as our operatives there began to chase after her," said spokesman Danbatta Bello, with the Civilian-JTF self-defence force.
"She rushed to the mosque and detonated the second bomb."
The first girl blew up where she was trapped, Mr Bello said.
Two other female suicide bombers were shot and killed in Maiduguri around the same time the mosque was attacked, Mr Bello said.
Boko Haram has increasingly used girls and young women to carry out attacks. Some young women who escaped the extremist group have said girls are drugged and forced to carry out suicide missions.
Nigeria's government late last year declared that Boko Haram had been "crushed" but deadly attacks continue.
The Islamic extremist group's insurgency has killed more than 20,000 people, seen thousands of others abducted and spilled over into neighbouring countries.
North-eastern Nigeria is part of what the United Nations has called the world's largest humanitarian crisis in more than 70 years, with the World Food Programme estimating that more than 4.5 million people in the region need emergency food assistance.
Boko Haram's insurgency has disrupted both agriculture and markets.