Islamic State (IS) extremists on Thursday executed around 300 Sunni Iraqis.
Security sources said the action was in retaliation for the government’s launch of a major offensive to regain the western province of Anbar from the radical militia, security sources said.
Sources said the victims, members of local Sunni tribes, were shot dead in the IS-held western town of Qaem near the border with Syria for alleged collaboration with government troops trying to recapture Anbar.
The Iraqi government started the onslaught to drive IS out of Anbar, the country’s largest province, on Wednesday.
Last week, Iraqi troops, backed by Shiite militiamen and US-led airstrikes, recaptured the strategic northern city of Tikrit in the hardest blow yet to the jihadists.
The Jihadists control vast parts of northern and western Iraq.
A security official said that government troops were on Thursday making significant advances in their push to retake mostly Sunni Anbar.
“Security forces, backed by Sunni and Shiite loyalists, have made “big progress” in driving militants out of Sijariya, east of Anbar’s, capital, Ramadi.
“Security forces are about to fully liberate Sijariya from the grip of Daesh,” he said, using the Arabic acronym for Islamic State.
“Several villages and suburban districts of Sijariya have been liberated,” Mohammed Hamed, a senior officer in the province’s police, said.
Six soldiers were killed and 15 wounded in battles with the jihadists in Sijariya, military sources said.
Meanwhile, government forces and volunteers were imposing a complete siege on Fallujah, a main Anbar city that has been under IS control for months.
“The next few hours will witness the storming of Fallujah, which is being besieged from all directions,” Shiite militia commander, Juma al-Jamili, told local media.
He said incursions into the city, around 60 kilometres west of Baghdad, had been hampered by booby traps planted by militants.
Most of Anbar, which stretches from Baghdad to Iraq’s border with Syrian, has been under the control of radical Sunni IS and anti-government Sunni insurgents since 2014.
Since taking office in September, Iraqi Shiite Prime Minister, Haider al-Abadi, has sought the backing of the country’s Sunni minority community in the fight to dislodge IS.
Iraq has in recent months stepped up the fight, with backing from a U.S.-led alliance.
IS also rules considerable territory in neighbouring Syria.