A sign left by Boko Haram
A signpost painted by Boko Haram is seen in the recently retaken town of Damasak in Nigeria's Borno stateReuters

A teenage girl who was strapped with an explosive vest fled from her Boko Haram handlers when she was told to blow herself up at a camp where people displaced by the terror group's insurgency resided. The girl, who has not been identified, was later found by local security forces.

Before she fled, the girl tried to persuade her two companions to abandon the mission "but she said she could not convince [them]". At least 58 people were killed when the duo blew up at Dikwa refugee camp, which is 85km northeast of Maiduguri.

"Women, children, men and aged persons all died," Modu Awami, a self-defence fighter who helped question the girl, was quoted as saying. "I cannot say the exact number as some cannot be counted because the bodies were all mangled," Awami added.

"She said she was scared because she knew she would kill people. But she was also frightened of going against the instructions of the men who brought her to the camp," Awami said. Some 50,000 people have taken shelter in Dikwa refugee camp fearing Boko Haram.

"She confessed to our security operatives that she was worried if she went ahead and carried out the attack that she might kill her own father, who she knew was in the camp," spokesman for the Ngala local government area, Algoni Lawan, said.

After being taken into custody, the girl disclosed information about other planned bombings, Satomi Ahmed, the chairman of the Borno State Emergency Management Agency, said.

Boko Haram has increased its number of suicide bombings using kidnapped girls and children. The six-year long insurgency carried out by the terror group has killed 20,000 people and left 2.5 million homeless.