Violent conflicts in Africa, fueled by the Boko Haram insurgency, have forced more than 1 million children out of school, the United Nations Children’s Fund reported Tuesday.

The organization, commonly known as UNICEF, reported that the children have been forced out of class in northeastern Nigeria and the neighboring nations of Cameroon, Chad and Niger.

UNICEF said that total doesn’t include the 11 million kids in those four countries who were already out of school before Boko Haram began its insurgency six years ago. According to the Global Terrorism Index, the Islamic extremist group killed more people last year (6,644) than any other terrorist organization — including the Islamic State, to which it has pledged allegiance.

But Boko Haram is only partly responsible for the violence in Nigeria.

Fulani militants, who use often violent tactics to control grazing land for their livestock, killed 1,229 people last year, according to the Global Terrorism Index. Because Nigeria houses two of the world’s five deadliest terrorist groups, the country had 7,512 terrorism-related deaths last year. That was more than any other country but Iraq, which established a record with 9,929.

According to UNICEF, more than 2,000 schools are closed in Nigeria, Cameroon, Chad and Niger. The organization says hundreds of them have been set ablaze, looted or otherwise attacked, and that some of the closures have stretched on for more than a year. In Cameroon, for example, UNICEF reported that 135 schools closed in 2014 and only one of them has reopened.

Part of the reason for the lengthy closures is that there’s a fear of future terrorist attacks. UNICEF reported that 600 Nigerian teachers have died during the Boko Haram insurgency.

Manuel Fontaine, UNICEF’s regional director in West and Central Africa, said in a statement that many children are now at risk of dropping out of school entirely as a result of the violence.

“The challenge we face is to keep children safe without interrupting their schooling,” Fontaine said in a statement. “Schools have been targets of attack, so children are scared to go back to the classroom; yet the longer they stay out of school, the greater the risks of being abused, abducted and recruited by armed groups.”

UNICEF said it’s taken some steps to help educate children in the region, like establishing some temporary learning spaces and expanding some schools, but they’ve reached less than 200,000 kids. Security issues and funding shortages have complicated the group’s outreach efforts.

UNICEF said it will need about $23 million to educate children in the four countries next year.