"Kurdish rebels are thought to have helped rescue around 20,000 from the mountain - but the same number is thought to still be trapped there. But who are the Yazidi, and why are they being persecuted?"
Persecuted: Yazidi children (pictured) have taken to sheltering in the holy valley of Lalish, while others trapped in the Sinjar Mountains were flown renewed supplies by the U.S. today. The religious minority is not alone in being threatened by the militants, who also say Christians and Shia Muslims are heretics and should convert.
Iraqis Yazidis, who fled their homes a week ago when Islamic State militants attacked the town of Sinjar, gather inside a building under construction where they found refuge on August 10, 2014 in the Kurdish city of Dohuk in Iraq's autonomous Kurdistan region.