Authorities in northeastern Nigeria say at least 13 people are dead after two female suicide bombers attacked a market.

Mohammed Maliya, who is part of the rescue effort in the town of Biu, says the victims were killed when one of the women detonated her explosives at a food distribution point run by a non-governmental organization.

She appeared relaxed and was eating a banana while waiting in line with others, Maliya says.

The other bomber killed only herself but wounded a number of people.

Saturday's attack took place about 185 kilometers (115 miles) from Maiduguri city, where the Islamic extremist group Boko Haram was formed.

The group has increasingly used women and children to carry out attacks. Many of them are kidnapped and indoctrinated in extremism.