An arial view of the burnt-out classrooms of a school in Chibok, in Northeastern Nigeria, from where Boko Haram Islamist fighters seized 276 teenagers in 2014. Picture: Sunday Aghaeze

Lagos - Four female suicide bombers exploded at a market in the Chibok hometown of Nigeria's kidnapped schoolgirls on Wednesday, killing 13 civilians and wounding 32 people, witnesses said.

Three soldiers including their commanding officer are among the injured being treated at the hospital, according to a man who was at the scene.

He said the blasts with shrapnel zapping through the air began when soldiers stopped a young women covered in a hijab for a routine search at the entrance to the open-air, roadside vegetable market in the northeast Nigerian town. She blew herself up. Then three women already inside the market exploded in quick succession. The man insisted on anonymity for fear of reprisals.

A Chibok community leader in Abuja, Nigeria's capital, said another blast occurred at a military checkpoint at the entrance to Chibok. Tsambo Hosea Abana said relatives called to tell him that his niece and uncle are among the wounded.

Residents blamed Boko Haram, the Islamic extremist group that kidnapped nearly 300 Chibok schoolgirls in April 2014. Dozens escaped but 219 remain missing. Chibok is a Christian enclave in Nigeria's predominantly Muslim north.

The plight of the girls brought Boko Haram international attention. The failure to rescue the schoolgirls contributed to the election defeat last year of former President Goodluck Jonathan. The militants have said some of the girls have converted to Islam and threatened to sell them into slavery. It also said some have been married to its fighters.

There has been no further news of the girls, though there are reports some were carried across Nigeria's borders.

Boko Haram's increasing use of girls and young women as suicide bombers has raised fears the militants are using captives as weapons.

ANA-AP