It was a chilly January evening, and Khadija Abd and her family had just finished supper at their farm when the two men with guns burst into the room.

One wore civilian clothes, the other an army uniform. They said they were from the Iraqi army’s 20th Division, which controls the northern Iraqi town of Badoush. In fact, they were Islamic State (IS) group militants who had come down from the surrounding mountains into Badoush with one thing on their mind: Revenge.