Saeed Mamouzini, a senior official from the Iraqi Kurdistan Democratic Party, said on Friday that 15 children, aged 13 to 18, were all killed after fleeing fighting in Baaj district, west of the militant-held Mosul.
The children, who had previously been recruited by ISIL militants, were killed in Sinjar district, north of Mosul, Mamouzini added.
The official noted that the ISIL terrorist group has abducted hundreds of children, mainly from Mosul, over the past few months and has forced them to take part in battles.
The children undergo military training and are given hard-line indoctrination following their recruitment.
Some videos released by the group show recruited children or teenagers executing captured soldiers and civilians.
Rights organizations have in numerous cases warned that the Takfiri group uses the children as spies or guards and encourages parents to send their kids to training camps.
Violence has plagued the northern and western parts of Iraq ever since ISIL launched its deadly terror campaign in June 2014, and took control of portions of Iraqi territory.
The terrorist group has gained notoriety for its barbarity, heinous atrocities, and sacrilegious acts. Its militants have been accused of committing war crimes in areas they control in Syria, Iraq, and Libya.