Among those threatened by the advance of the Islamic State are thousands of members of Iraq’s Yazidi ethnic minority, trapped in mountains in the northwest of the country.

The Islamic State has threatened to kill more than 300 families unless they convert to Islam, according to a Yazidi politician and witnesses in the area.

The families, situated in the villages of Koja, Hatmiya and Qaboshi, are surrounded militants who have captured large swathes of northern Iraq since June.