Islamic State rebels have executed 67 people from a pro-government Sunni tribe in the western Iraqi province of Anbar, a tribal leader said Sunday, the latest mass killing carried out by the radical group.

“Daesh executed last night (Saturday) 67 members of the al-Bu Nimr tribe including children and women,” Naeem al-Kaud, a senior al-Bu Nimr leader, said using an Arabic acronym for the Islamic State.

He told Iraqi site Alsumaria News those executed were among 200 tribal captives held by the rebels in the town of Ras al-Maa north of Anbar.

“The 125 others also face the threat of death,” he said.

Islamic State fighters have scored a number of advances in Anbar in recent weeks, threatening to gain full control of the Sunni-populated province, which stretches from the Syrian border to the outskirts of the capital Baghdad.

The al-Qaeda splinter group has been accused in the past few days of carrying out a series of executions against members of the al-Bu Nimr tribe, which is fighting alongside government troops against the Islamic State.

The radical Sunni group has reportedly committed in recent months mass killings in neighbouring Syria where it also controls considerable territory. SAPA