The number of children forced by Boko Haram to blow themselves up as "suicide" bombers increased more than tenfold last year, a United Nations agency said Tuesday.
An estimated 44 children, some as young as 8 years old, were made to carry out attacks across Nigeria, Cameroon and Chad last year, according to report by children's agency UNICEF. This was up from just four in 2014.
"Let us be clear — these children are victims, not perpetrators," regional UNICEF director Manuel Fontaine said in a statement accompanying Tuesday's report.
"Deceiving children and forcing them to carry out deadly acts has been one of the most horrific aspects of the violence in Nigeria and in neighboring countries," he added.
The Nigerian government claims it has all but defeated Boko Haram, the ISIS-affiliated Islamist sect that has killed thousands and displaced more than 2 million people during its seven-year campaign of terror.
But the attacks have continued, and many analysts believe the army's territorial gains have prompted the militants to prey on soft targets.
UNICEF's report, entitled "Beyond Chibok," was published two days before the second anniversary of Boko Haram's kidnapping of more than 270 schoolgirls from the Nigerian town of Chibok.
Although the Chibok abduction was one of the largest cases — sparking the ultimately fruitless #BringBackOurGirls appeal — Boko Haram is believed to have kidnapped more than 2,000 people in total.
Expects have suggested the group maybe using its captives as suicide bombers.
According to UNICEF, the number of suicide bombings in Nigeria, Cameroon, Chad and Niger rose from 32 in 2014 to 151 last year. One in five of these attacks used children as vehicles for the explosives.
"Boys are forced to attack their own families to demonstrate their loyalty to Boko Haram, while girls are exposed to severe abuse including sexual violence and forced marriage to fighters," the report said. "Some are also used to carry or detonate bombs."
More than 1.3 million children have been displaced, and even those not used as suicide bombers face "exploitation, abuse and recruitment by armed groups," according to the report. These children are also exposed to sexual violence, their schools are attacked and their humanitarian access is limited.
Even those who escape Boko Haram are often shunned by their families on their return home.
Women and girls are often shunned by their communities, either because they are carrying children after being raped by Boko Haram fighters or because their family believe they may have been radicalized while in captivity.
UNICEF is using the hashtag #BringBackOurChildhood to raise awareness for its appeal for donations.