The UN Committee on the Rights of the Child says that Iraqi children are being abducted and sold into sex slavery. The report details a number of atrocities, including the killing youths by crucifixion - and burying them alive.
It also finds that Iraqi boys and young men (under 18) are being used as suicide bombers, bomb makers, informants and as human shields.
Committee-expert Renate Winter spoke to Reuters, saying: "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."
He continues: "We are really deeply concerned at [the] torture and murder of those children, especially those belonging to minorities, but not only from minorities."
The committee condemned "the systematic killing of children belonging to religious and ethnic minorities by the so-called ISIL (IS), including several cases of mass executions of boys, as well as reports of beheadings, crucifixions of children and burying children alive."
It also found that children under the age of eight are being trained to become child soldiers.
While ethnic minorities have been particularly targeted by the Sunni group - children from the Yazidi Krrdish sect, Christian communities, and both Shi'ite and Sunni Muslims have all been victims.
Erin Evers, an Iraq researcher for Human Rights Watch, spoke to VICE News, she welcomed the report - but added that it is long overdue.
Ms Evers warned that other groups, including Shia militias working under the Iraqi government are also engaging in abuses:
"We have seen evidence that they are recruiting children, but there's been very little reporting on it. IS advertises its training and abuse of children, whereas it's harder to research on what the militias are doing."
Laurent Chapuis, UNICEF's Middle East and North Africa adviser on child protection also discussed the report with VICE News - he says:
"The recruitment and use of children by all parties has become a common feature of the conflict… there are a number of unique features with regards to ISIL's (IS) recruitment and use of children."
IS publicises its use of children for propaganda purposes.
The militants expose children to extreme violence to desensitize them - they are encouraged them to attend, and to participate in public executions.
The UN findings are based on information supplied by the Iraqi government, non-governmental organisations, and Iraq's UN delegation.
Robert Fisk, Middle East correspondent for The Independent discussed the Islamic State on The Pat Kenny show - he says that the group's acts are beyond-barbarism.
