DAKAR, Senegal (AP) — The United Nations Children's Fund says Boko Haram's ongoing insurgency in northern Nigeria has forced the closure of more than 57 percent of schools in Borno state, leaving about 3 million children out of education as the school year begins.

The U.N. agency said in a report Friday that nearly 2,300 teachers have been killed in Nigeria's northeast since 2009 by Boko Haram and nearly 1,400 schools have also been destroyed.

UNICEF Deputy Executive Director Justin Forsyth says that while saving children from malnutrition and illness is essential, children must keep learning to overcome trauma and give hope.

The U.N. Humanitarian agency says only 12 percent of funding for education in Nigeria has been received. The extremists' eight-year insurgency has killed more than 20,000 people in the Lake Chad region.