Around 800,000 children have been forced to flee Boko Haram's campaign of violence in Nigeria, according to a new United Nations report published Monday.
UNICEF's "Missing Childhoods" report was released on the eve of the anniversary of the mass abduction of 276 schoolgirls from the rural town of Chibok which captivated the world. Most of those girls remain in captivity, scores more of their peers have since gone missing, and the number of children forced from their homes by the violence has more than doubled in less than a year, according to the report.
“The abduction of more than 200 girls in Chibok is only one of endless tragedies being replicated on an epic scale across Nigeria,” Manuel Fontaine, UNICEF's regional director for West and Central Africa, said in a statement.
Many children forced to flee have been separated from their parents, according to UNICEF. The organization found nearly 2,400 separated and unaccompanied children when it surveyed 150,000 displaced persons in 33 locations in Nigeria.
"Many have had to run for their lives and walk for days to reach safety," the report said. "Others have been exposed to extreme violence and abuse."
More than 1.5 million people have fled their homes due to Boko Haram-related violence — and at least 15,000 people have died since 2009, when Boko Haram stepped up its campaign of terror.
Many children have been displaced "not just once but several times," UNICEF's spokesman for West and Central Africa, Laurent Duvillier, told NBC News.
"They are literally being hunted by Boko Haram, village after village," he added. “They’ve seen with their own eyes sometimes their parents killed, sometimes their brothers and their sisters abducted… Many of these children cannot sleep, speak or eat normally because they are so affected by what they've seen."
The U.N. human rights chief warned this month that the Islamist extremist group was using children as "expendable cannon fodder" and "human bombs."
The UNICEF report released Monday stated that children "have become deliberate targets, often subjected to extreme violence — from sexual abuse and forced marriage to kidnappings and brutal killings."
Boko Haram is using children as young as four years old — as cooks, porters and lookouts — within its ranks, the report added.
"Young women and girls who have been abducted have been subjected to forced marriage, forcible religious conversion, physical and psychological abuse, forced labor and rape," the report said, citing accounts of escapees.
Fighting related to the group also has deprived children of access to education: 10.5 million children of primary school age in Nigeria are not attending school — the highest figure in the world, according to UNESCO figures.
"Throughout northeast Nigeria and across the border regions in Cameroon, Chad and Niger, children are in critical danger," according to the report.
UNICEF spokesman Duvillier stressed that the world cannot forget the "unacceptable" kidnap of the Chibok schoolgirls — which launched the #BringBackOurGirls hashtag — but also must pay heed to the hundreds of other children who have been taken since.
"We call for a new hashtag — #BringBackOurchildhood —not just girls," he told NBC News. "Many other children have been abducted… and are today away from home.