DAKAR, Senegal — As it torments West Africa, Boko Haram is increasingly turning to children to carry out its crimes.

One of every five suicide bombers deployed by Boko Haram in the past two years has been a child, usually a girl, according to a report released Tuesday by Unicef.

Boko Haram used 44 children in suicide attacks last year, compared with only four in 2014, the report found.

The youngest bomber so far was thought to be 8 years old.

The report seeks to quantify one of the most chilling elements of Boko Haram, an Islamist extremist group that has assaulted the Lake Chad region of Africa for years with thievery, beheadings, kidnappings and the torching of entire villages. The group has killed thousands of people and caused a food crisis, leaving the area hungry and in tatters.