The largest camp for Nigerian refugees who have fled Boko Haram is located east of the Mambara Mountains, on a sandy plain covered with cotton, sorghum and corn fields.

Here, they are miles away from the slaughter, rape and abductions of one of Africa’s most unpitying terrorist groups, though many are yet to recover from the trauma of seeing so much blood, enduring torture or watching close relatives die.

Most are children. Barefooted and often without adequate clothing against the scorching heat, they spend the day plucking wild vegetables, gathering firewood or taking lessons from the camp’s primary school.The life they live is everything but normal.

This week, the United Nations Children Fund (UNICEF) exposed the “devastating impact” on children, of Boko Haram’s bloody campaign to establish and Islamic caliphate in northeast Nigeria and Cameroon.

Since the bombings, torching of schools and other atrocities started, more than 800,000 children have been forced out of their homes in Nigeria and other neighbouring countries, the Fund said in a new report: Missing Childhoods.

The report was released to coincide with the first anniversary of the kidnap of more than 200 schoolgirls from Chibok in northeast Nigeria last year. The majority are still in captivity, while a few dozen have escape to narrate tales of enslavement and rape.

“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,” says Manuel Fontaine, UNICEF Regional Director for West and Central Africa.

“Scores of girls and boys have gone missing in Nigeria – abducted, recruited by armed groups, attacked, used as weapons, or forced to flee violence. They have the right to get their childhoods back.”

The number of children fleeing the conflict has more than doubled over the last year, UNICEF says. It reflects the rapidly growing humanitarian crises created by the conflict, which is affecting the Lake Chad region’s Muslims and Christians alike.

Though Boko Haram is behind most of the barbarities committed against children, military intervention and the reprisals of local vigilante groups have also contributed to the number of children displaced by the conflict.

The report noted that: • Children are being used within the ranks of Boko Haram – as combatants, cooks, porters and look-outs. • Young women and girls are being subjected to forced marriage, forced labour and rape. • Students and teachers have been deliberately targeted – with more than 300 schools damaged or destroyed and at least 196 teachers and 314 schoolchildren killed by the end of 2014.

“UNICEF has stepped up its humanitarian response to the crisis,” says the agency in a statement. “Over the past six months, UNICEF has provided over 60,000 children affected by the conflict in Nigeria, Niger, Cameroon and Chad with counselling and psychosocial support to help them ease the pain of their memories, reduce stress and cope with emotional distress.

“UNICEF is also working with partners to provide safe water and life-saving health services, restore access to education by creating temporary learning spaces, and deliver therapeutic treatment to malnourished children.”

But it is not getting enough money to deal with the growing challenge. “UNICEF has received only 15 per cent of the US$26.5 million required for its humanitarian response in Nigeria for 2015, and no more than 17 per cent for its overall humanitarian funding appeal for Cameroon, two per cent for Niger and two per cent for Chad,” says the agency.

“Faced with a severe funding shortfall,” UNICEF says it is “urging international donors to ramp up their financial support for relief efforts in Nigeria and the neighbouring countries.”