Following claims by Al-Qaeda-inspired fighters that they had executed 1,700 Iraqi soldiers who were fleeing battles earlier this month, Human Rights Watch confirmed a massacre had likely taken place and said the evidence points to specific locations in Tikrit.

The Islamic State of Iraq and the Levant (ISIL) posted several photos online in mid-June showing what it said were the bodies of Iraqi soldiers who had surrendered after ISIL-led forces expanded their control in the predominantly Sunni part of the country.

"Analysis of photographs and satellite imagery strongly indicates that [ISIL] conducted mass executions in Tikrit after seizing control of the city on June 11, 2014," Human Rights Watch (HRW) said, suggesting a death toll under 200. "The number of victims may well be much higher, but the difficulty of locating bodies and accessing the area has prevented a full investigation."

HRW cross-checked landmarks and other publicly available photos where the killings were said to have occurred, said Fred Abrahams, a special adviser for the group.

“We then used old satellite imagery and new imagery [taken the morning of June 16] to locate one of the execution sites, about 100 meters north of Saddam Hussein’s former Water Palace in Tikrit,” he said. “Based on the photos we’re examining, we’re estimating 160 to 190 killed at that site.

“The details in the photos were consistent, which bolsters their veracity,” he said. “It’s not absolute proof, but it gives evidence they’re real.”