A woman suicide bomber in Boko Haram-hit northeast Nigeria strapped a baby to her back to go unnoticed as she walked into a busy market to detonate her explosives in a recent attack, a local government official said.
The woman with a baby and two girls, all carrying explosives, struck a crowded market in the town of Madagali, killing six people and injuring 17, according to the chairman of Madagali local government, Alhaji Yusuf Mohammed.
Nigerian army spokesman Rabe Abubakar could not confirm that a baby had been used in the attack, and said the woman may have just been disguised to appear as if she was carrying an infant.
The UN children's agency (UNICEF) said it was the first such incident involving a baby reported in northeast Nigeria.
We are extremely worried about the use of a baby in this callous way
"We are extremely worried about the use of a baby in this callous way," UNICEF spokeswoman Doune Porter told.
The suicide bombings, which bore the hallmark of jihadist group Boko Haram, are common in northeast Nigeria, the heart of the militants' seven-year campaign to create an Islamic state.
The Islamist group preys on displaced children or young girls it kidnaps and forces them to become bombers, with some unaware they are carrying explosives, aid agencies say.
The use of children as suicide bombers by Boko Haram has surged almost five-fold since 2014, with 19 child bombings, most involving young girls, recorded by UNICEF.
Prior to the Madagali bombings, the youngest child used in such an attack was a nine-year-old girl, the UN agency said.
The attack in Madagali is one in a series of bombings in Nigeria northeast, mainly Borno state, in recent weeks as Boko Haram steps up attacks with the end of the rainy season facilitating movements in the bush.
However, risk management consultancy Signal Risk's director Ryan Cummings said Nigeria's civilian joint task force (CJTF) had stepped up efforts to spot and search suspected bombers.
"Several attempted attacks by females bombers have been thwarted (due to the CJTF), limiting casualties," he said.
Army spokesman Abubakar said security forces would be extra vigilant and ready to respond to any new strategies used by Boko Haram.