Islamic State of Iraq and Syria (ISIS) militants have killed 322 members of an Iraqi tribe in western Anbar province, including dozens of women and children whose bodies were dumped in a well, the government said in the first official confirmation of the scale of the massacre.

The systematic killings, which one tribal leader said were continuing on Sunday, marked some of the worst bloodshed in Iraq since the Sunni militants swept through the north in June with the aim of establishing medieval caliphate there and in Syria.

The Albu Nimr, also Sunni, had put up fierce resistance against ISIS for weeks but finally ran low on ammunition, food and fuel last week as ISIS fighters closed in on their village Zauiyat Albu Nimr. […]