The UN agency, in a report ‘How the world failed children in conflict in 2018’, also said the world failed to protect children in conflict in Nigeria and 14 other countries in 2018.
UNICEF said the future of millions of children living in Nigeria and other countries affected by armed conflict were at risk, as warring parties continued to commit grave violations against children, and world leaders failed to hold perpetrators accountable.
The other countries are Afghanistan, Cameroon, Central African Republic, Democratic Republic of the Congo, Iraq, Mali, Burkina Faso, Niger, Myanmar, Palestine, South Sudan, Somalia, Syria, Ukraine, and Yemen.
UNICEF added that children living in countries at war had come under direct attack, had been used as human shields, killed, maimed or recruited to fight.
The UN children agency said rape, forced marriage and abduction had become standard tactics employed by the mainstream Boko Haram terrorists and the factional Islamic State West Africa Province.
UNICEF said: “In northeast Nigeria, armed groups, including Boko Haram factions, continue to target girls, who are raped, forced to become wives of fighters or used as ‘human bombs’.
“In February, the group abducted 110 girls and one boy from a technical college in Dapchi, Yobe State.
“While most of the children have since been released, five girls died and one is still being held captive as a slave”.
In the Lake Chad basin, ongoing conflict, displacement and attacks on schools, teachers and other education facilities have put the education of 3.5 million children at risk, UNICEF said.
“Today in northeast Nigeria, the Lake region of Chad, extreme north of Cameroon and Diffa region of Niger, at least 1,041 schools are closed or non-functional due to violence, fear of attacks, or unrest, affecting nearly 445,000 children.”
Across all these countries, UNICEF said it worked with partners to provide the most vulnerable children with health, nutrition, education and child protection services.
“For example, in October, UNICEF helped to secure the release of 833 children recruited into armed forces in northeast Nigeria, and is working with partners to reintegrate them into their communities,” it said.
UNICEF Director of Emergency Programmes, Mr Manuel Fontaine, said children suffering atrocities and the number of countries in conflict hit new peak in 2018.
“Children living in conflict zones around the world have continued to suffer through extreme levels of violence over the past 12 months, and the world has continued to fail them.
“For too long, parties to conflict have been committing atrocities with near-total impunity, and it is only getting worse. Much more can and must be done to protect and assist children.
“2019 marks the 30th anniversary of the landmark Convention on the Rights of the Child and the 70th anniversary of the Geneva Conventions, yet today, more countries are embroiled in internal or international conflict than at any other time in the past three decades.
“Children living through conflict are among the least likely to be guaranteed their rights. Attacks on children must end,” Fontaine said.
UNICEF called on warring parties to abide by their obligations under international law to immediately end violations against children and the targeting of civilian infrastructure, including schools, hospitals and water infrastructure.
UNICEF also called on states with influence over parties to conflict to use that influence to protect children.
“Much more needs to be done to prevent wars, and to end the many disastrous armed conflicts devastating children’s lives.
“Yet even as wars continue, we must never accept attacks against children. We must hold warring parties to their obligation to protect children.
“Otherwise, it is children, their families and their communities who will continue to suffer the devastating consequences, for now, and for years to come,” Fontaine said.