Two female suicide bombers killed at least 21 people yesterday in a busy market area of Nigeria’s northeastern city of Maiduguri, centre of a militant Islamist insurgency, emergency services said.

Four witnesses said a woman had entered the roadside trading area behind the city’s main market before blowing herself up.

“While the people were trying to help the injured, the second bomb blasted,” witness Sani Adamu said. “I saw lots of bodies”.

An official at the National Emergency Management Agency (Nema) said 21 bodies had so far been removed from the scene of the twin blasts, while a medical worker said a local hospital where he was based had received some 13 bodies.

Nigerian authorities did not immediately respond to requests for comment. There was no claim of responsibility, but suspicion is likely to fall on violent Islamist group Boko Haram, whose five-year campaign for an Islamic state has killed thousands.

The group has increasingly used female suicide bombers.

In June, there were four attacks by female bombers in the largely Muslim north, including one targeting a school in Kano, the region’s biggest city.

Another woman blew herself up at a teacher training college in Nigeria’s central Niger state on November 12, killing at least one other person.

Adamu said he counted more than 30 people on the ground, but did not know if they were dead or wounded.