BAGHDAD (Reuters) - Islamic State has executed 85 more members of the Albu Nimr tribe in Iraq, a tribal leader and security official said on Saturday, part of a mass killing campaign launched last week to break local resistance to the group's territorial advances.

Tribal chief Sheikh Naeem al-Ga'oud told Reuters Islamic State had killed 50 members of Albu Nimr who were fleeing the group in Anbar province on Friday. A further 35 bodies were found in a mass grave, a security official said.

Islamic State has executed a total of more than 300 tribe members in the past few days, Ga'oud and the official said.

The sustained bloodshed appears to demonstrate the group's resilience to the U.S. air strikes that have been targeting its fighters in Iraq and Syria.

Ga'oud said he had repeatedly asked the Shi'ite-led central government in Baghdad for arms but that his pleas were ignored.

Albu Nimr had held out for weeks under siege by Islamic State, but finally ran low on ammunition, fuel and food.

Hundreds of tribal fighters withdrew and the tribe fled its main village of Zauiyat albu Nimr, but many were intercepted by the militants who shot them at close range and dumped in mass graves.

Islamic State's advances have fueled sectarian bombings, kidnappings and shootings which occur almost daily in Iraq, echoing the peak of a civil war in 2006-2007.

Also on Saturday, a truck bomb killed 13 people at a vegetable market in the town of Yusufiya just south of Baghdad, police and medical sources said.

In the capital's Doura neighborhood, a bomb killed seven people, including four policemen, security and medical sources said.


In Anbar, fighters have encircled a large air base and the vital Haditha dam on the Euphrates. They also control territory ranging from towns on the Syrian border to parts of provincial capital Ramadi and the lush irrigated rural areas near Baghdad.

Anbar was the main battleground between U.S. Marines and al Qaeda during the "surge" campaign in 2006-2007, when American troops enlisted the help of local tribes, including Albu Nimr.

Ga'oud said the 50 tribe members were killed near Tharthar Lake near a desert area. They had been traveling on foot when they were intercepted by the Sunni militants.

He said one managed to escape the carnage and get word to tribal leaders.

"Forty of the dead were men. Six women and four children were killed while trying to protect their husbands and fathers," said Ga'oud.

His account was confirmed by Faleh al-Essawi, the chief of the security committee of the Anbar Provincial Council.

In the other incident, 35 corpses were found on the outskirts of Ramadi. "They were handcuffed and blindfolded. Some were wearing tracksuits and others were wearing dish-dash robes," an eyewitness told Reuters.

Iraq's Shi'ite Prime Minister Haider al-Abadi wants Sunni tribal leaders to support the Iraqi army against Islamic State, which has threatened to march on Baghdad. But mistrust has undermined efforts to revive an alliance.