More than 800,000 children, some as young as 4, have been forced to flee their homes since last year because of Boko Haram’s violent attacks on military forces and civilians in Nigeria, according to a new United Nations report.

The report, “Missing Childhoods,” was released Monday, one year after the radical Islamist group conducted a mass abduction of more than 200 schoolgirls from the rural town of Chibok. It reveals that thousands of children are running for their lives, seeking safety.

“The abduction of more than 200 girls in Chibok is only one of endless tragedies being replicated on an epic scale across Nigeria and the region,” said Manuel Fontaine, UNICEF regional director for West and Central Africa. “They have the right to get their childhoods back.”

The destructive attacks on families “is exerting a heavy toll on children in Nigeria,” the 11-page report reads. Many who are forced to flee have been separated from their parents, UNICEF said, and Boko Haram is using the ones they caught as combatants, cooks, porters, look-outs and soldiers. The young women and girls, in particular, are subjected to forced marriage and labor, and are also being raped, according to the report.

The violence in Nigeria is also preventing children from having access to education, the report said. Some 10.5 million children of primary school age are not attending school—the highest figure in the world, according to UNESCO figures.

“More than 300 schools have been severely damaged or destroyed, and at least 196 teachers and 314 school children were killed in the period between January 2012 and December 2014,” the report reads.

As the horrors of mass abduction continue to gain worldwide attention around the hashtag #BringBackOurGirls. Many are hoping that the girls will be rescued. Tuesday marked the first anniversary of the April 14 and 15, 2014, mass kidnapping, President-elect Muhammadu Buhari said he cannot promise the government will find them, the Associated Press reported.

“We do not know if the Chibok girls can be rescued,” the AP cited him saying in a statement. “Their whereabouts remain unknown. As much as I wish to, I cannot promise that we can find them.”

Buhari, a former military ruler of Nigeria, was democratically elected last month. Nigeria’s current president, Goodluck Jonathan, received scathing criticism for denying that there had been a kidnapping and his administration’s failure to rescue the girls.

Buhari said he hears “the anguish of our citizens and intend to respond accordingly.” He added that “this new approach must also begin with honesty,” the AP reports.