Iraq residents confirmed that the IS group carried out a mass execution near the northern city of Tikrit
The Islamic State (IS) group has released pictures of the execution of 13 men described as anti-jihadist Sunni tribal fighters near the northern city of Tikrit.
Three pictures published on a jihadist forum and pro-IS social media accounts showed the execution of the men wearing orange jumpsuits on Monday.
Local residents confirmed to AFP news agency that a mass execution had taken place on a large roundabout six kilometres east of Tikrit.
The first picture shows 11 men kneeling, heads bowed, with one black-clad and masked gunman behind each one and black IS flags in the background.
The next picture shows the gunmen brandishing their handguns after the execution and in the third a small gathering of onlookers, including children, can be seen near 13 bodies, which have been dragged off the roundabout's central island and onto the road.
Residents said the roundabout is at an intersection for roads leading to Tikrit, Kirkuk and the town of al-Alam.
They said the men who were executed were members of an anti-IS group of Sunni tribal fighters known as the Knights of al-Alam who were captured by jihadists in Tikrit and al-Alam around 10 days earlier.
The city of Tikrit has been under IS control since the beginning of the group's major offensive in Iraq six months ago.
Iraqi government forces, backed by Shiite militia and in some areas by Sunni tribal fighters, have inflicted a string of defeats against IS in recent weeks.