Human Rights Watch based its conclusions on interviews with several children who were among more than 150 Kurdish boys from Kobani abducted in late May as they were returning home after taking school exams in the city of Aleppo. It said around 50 of the Kurds escaped early in their captivity, while the rest were released in batches the last coming on Oct 29.
"Since the beginning of the Syrian uprising, children have suffered the horrors of detention and torture, first by the Assad government and now by ISIS," said Human Rights Watch's Fred Abrahams. "This evidence of torture and abuse of children by ISIS underlines why no one should support their criminal enterprise."
The boys said that some of the worst abuse was reserved for captives who had family members in the Kurdish militia known as the YPG, which has been locked in heavy fighting with Islamic State militants for control of Kobani since mid-September.
The children said the Islamic State group did not say why they were being released, other than that they had completed their religious training, the Human Rights Watch report said. Islamic State militants have taken hundreds of Kurds captive over the past year as part of the group's brutal campaign to take over predominantly Kurdish areas of northern and eastern Syria.