More than 1 million children can no longer attend school in Nigeria and neighboring countries due to ongoing violent attacks by Islamic extremist group Boko Haram, according to a new UNICEF report released Tuesday.

The violence has forced more than 2,000 schools in northeastern Nigeria, Chad, Niger and Cameroon to close, the agency said. Boko Haram, whose name roughly translates to "Western education is forbidden," has attacked, looted or burned hundreds of more schools, according to The Associated Press.

"The conflict has been a huge blow for education in the region, and violence has kept many children out of the classroom for more than a year, putting them at risk of dropping out of school altogether," said Manuel Fontaine, UNICEF's West and Central Africa regional director, warning that the "staggering" number of children out of school increases the chances that they will be "abused, abducted and recruited by armed groups."

Fontaine continued: "The challenge we face is to keep children safe without interrupting their schooling. 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."

Since Boko Haram began its terror campaign in 2009, more than 20,000 people have been killed, including 600 teachers, and 2.3 million have been displaced, including 800,000 children.

The country's president, Muhammadu Buhari, gave the military until the end of December to defeat the group, according to BBC. But considering that Boko Haram is still bombing areas despite losing ground, the deadline is likely to be extended.

Some U.S. lawmakers are reportedly blaming former secretary of state Hillary Clinton for the rise of Boko Haram, noting that she never classified the group as a terrorist organization during her tenure as the nation's top diplomat from 2009 to 2013, according to Breitbart.

President Obama announced in October that he would deploy 300 troops to Cameroon to conduct intelligence and pursue Boko Haram, reported the Guardian.