In a night attack on Kurdish forces in the winter of 2015 ISIS militants captured 45 Peshmerga soldiers who have been missing since. The same year ISIS paraded the captives in public in the town of Hawija west of Kirkuk.
Since the group's defeat last year ten mass graves have been located in the vicinity of Hawija, but the remains of only three Peshmerga were found in them.
The fate of the rest is unknown.
Local residents who fled ISIS rule believe ISIS took the rest of the captives with them as they fled the area towards Syria.