Islamic State militants are selling abducted Iraqi children at markets as sex slaves, and killing other youth, including by crucifixion or burying them alive, a United Nations watchdog said yesterday.

Iraqi boys aged under 18 are increasingly being used by the militant group as suicide bombers, bomb makers, informants or human shields to protect facilities against US-led air strikes, the UN Committee on the Rights of the Child said.

“We are really deeply concerned at torture and murder of those children, especially those belonging to minorities, but not only from minorities,” committee expert Renate Winter told a news briefing. Children from the Yazidi sect or Christian communities, but also Shi’ites and Sunnis, have been victims, she said.

“We have had reports of children, especially children who are mentally challenged, who have been used as suicide bombers, most probably without them even understanding,” Winter told Reuters. Islamic State is a breakaway al-Qaeda group that declared an Islamic caliphate across parts of Syria and Iraq last summer. It has killed thousands and forced hundreds of thousands from their homes, in what the UN has called a reign of terror.

The UN body, which reviewed Iraq’s record for the first time since 1998, denounced “the systematic killing of children belonging to religious and ethnic minorities by the so-called Isil, including several cases of mass executions of boys, as well as reports of beheadings, crucifixions of children and burying children alive”.

Isil has committed “systematic sexual violence”, including “the abduction and sexual enslavement of children”, it said. “Children of minorities have been captured in many places... sold in the market place with tags, price tags on them, they have been sold as slaves,” Winter said, giving no details.