The UN body said 27 children -- mostly girls – had been used in suicide attacks in the Lake Chad region in the first quarter of 2017, compared to nine in the same period last year.
"In the first three months of this year, the number of children used in bomb attacks is nearly the same as the whole of last year -- this is the worst possible use of children in conflict," said UNICEF’s Regional Director for West and Central Africa, Marie-Pierre Poirier.
"These children are victims, not perpetrators," Poirier added.
Noting that Boko Haram had increased its “alarming tactic” of using children as suicide bombers, UNICEF said 117 children carried out bomb attacks in public places across Nigeria, Chad, Niger and Cameroon since 2014.
"Girls have been used in the vast majority of these attacks," UNICEF added.