Armed conflict has had a terrible impact on children in 2014, according to a new report by UNICEF that details the damage suffered by young people who have been killed, conscripted, orphaned, displaced, traumatized and made homeless by war.

Around 15 million children were directly affected by major conflicts around the world, including the Central Africa Republic (CAR), Syria, South Sudan, Iraq, Ukraine and Palestine. “This has been a devastating year for millions of children,” Anthony Lake, UNICEF’s Executive Director, said in a statement. “Children have been killed while studying in the classroom and while sleeping in their beds.”

The report chronicles children's experiences of conflict and warns that the world’s attention is flagging, despite reports of worsening violence. In the CAR, for example, more than 430 children were killed or maimed this year, three times as many as in 2013. In total, 2.3 million children were affected by the war in the CAR, the U.N. children’s agency estimates, including at least 10,000 who have been used as child soldiers.

Meanwhile a record 1.7 million refugees from the Syrian conflict are under the age of 18. Children were attacked at schools in at least 35 different instances in Syria, and are increasingly at risk of contracting polio, a disease that has re-emerged in the country following the collapse of the public health system.

Many Syrian refugee children are forced to work or are married off to help support their families. One in ten has dropped out of school to earn money, said Najwa Mekki, communications specialist at UNICEF. In Jordan, one in three Syrian girls is now a child bride, she added.

In Gaza more than 500 children were killed during the 50-day conflict this summer, UNICEF reports, and 54,000 children were left homeless.

“Violence and trauma do more than harm individual children. They undermine the strength of societies,” Lake said. “The world can and must do more to make 2015 a much better year for every child.”

UNICEF also called attention to children in West Africa who have been killed or orphaned by Ebola. The outbreak in Guinea, Liberia and Sierra Leone has left an estimated 5 million children out of school.

This year has also been a harsh one for children in rich countries, the agency noted in a separate report. The global economic crisis has forced around 2.6 million children below the poverty line in members of the Organization for Economic Cooperation and Development since the beginning of the recession in 2008.

"Many affluent countries have suffered a great leap backwards in terms of household income, and the impact on children will have long-lasting repercussions for them and their communities," said Jeffrey O’Malley, UNICEF’s Head of Global Policy and Strategy.

In the United States, child poverty has increased in 34 out of 50 states, the agency found.