The UN office working on behalf of children caught up in armed conflicts has launched a guidance note to strengthen the monitoring and reporting on the abduction of children.
It also provides tools to address the increasing problem, said the report published by the Office of the Special Representative of the Secretary-General for Children and Armed Conflict.
"The abduction of children in situations of armed conflict is one of the most difficult to document," said Virginia Gamba, head of the office, in her preface to the 50-page note.
She said that abducted children often disappear for months, "sometimes years, and the experiences they go through while held in captivity often have long-term negative effects in their lives."
Some of the children, once released or once they manage to escape, face significant challenges in being reintegrated into their communities, she said.
The problem needs to be addressed by the United Nations and its partners so that children can benefit from long-term and tailored reintegration programs.
"Abducted children, and especially girls, are often targeted on their way to or while at school," the special representative said.
"Children can be abducted for a wide variety of exploitative purposes, including but not limited to recruitment and use, rape and other forms of sexual violence, and ransom, among others."