A surge in attacks by Boko Haram have claimed the lives of nearly 400 people since April in Nigeria and Cameroon; nearly double the number in the previous 5 months according to Amnesty International.

Boko Haram is increasingly using suicide bombers - mainly young women and girls, forced to carry and detonate explosive in crowded locations. 

"Boko Haram is once again committing war crimes on a huge scale, exemplified by the depravity of forcing young girls to carry explosives with the sole intention of killing as many people as they possibly can," said Alioune Tine, Amnesty International's director for West and Central Africa.

"The recent spike in casualties has been driven by increased suicide attacks, with 30 - more than one per week - carried out since the beginning of April," says the human rights agency.

The group initially claimed to building an Islamic state after pledging allegiance to Daesh in March of 2015, but a range of demands by different people have since been issued.

At least 20,000 people have been killed in violence since 2009 and more than 2.6 million people have been left homeless. Over 5 million are left starving due to devastated farmland.

The violence and lack of security also forces thousands of parents to refuse sending their children to school, with UNICEF adding that escaped or released children are viewed with suspicion or rejected by their communities.