Islamic State of Iraq and Syria (ISIS) militants executed at least 220 Iraqis in retaliation against a tribe’s opposition to their takeover of territory west of Baghdad, security sources and witnesses said.

Two mass graves were discovered on Thursday containing some of the 300 members of the Sunni Muslim Albu Nimr tribe that ISIS had seized this week. The captives, men aged between 18 and 55, had been shot at close range, witnesses said.

The bodies of more than 70 Albu Nimr men were dumped near the town of Hit in the Sunni heartland Anbar province, according to witnesses who said most of the victims were members of the police or an anti-ISIS militia called Sahwa (Awakening). […]