The Monday-morning yoga class is full of young women. As the instructor tells them to breathe slow and deep, they squirm and fidget, struggling to settle. Tacked on the walls are drawings, including one of four girls in hijabs chained together. Every member of the class, including the instructor, has survived being kept as a sex slave by Isis fighters, raped and repeatedly sold on. A few weeks ago, one of the group, Khalida, 20, committed suicide by hanging herself.

Outside stretches a muddy field of white canvas tents. Khanke camp, near Dohuk, northern Iraq, shelters some of the 420,000 Yazidis who were forced from their homes when Isis swept into their areas in northern Iraq in August 2014. Men were slaughtered, women and girls