Mass graves containing up to 400 victims of the Islamic State were discovered by Iraqi security forces on Saturday in an area that was recently recaptured from the terror group.
Bodies of security forces and civilians were found in a former military base near the town of Hawija, which was liberated in early October.
"Not less than 400 people were executed," Kirkuk Governor Rakan Saeed said, noting that some were wearing the uniform of prisoners while others wore civilian clothing.
According to Kurdistan 24, the bodies were found at al-Bakara base, which used to be an American base before it was vacated in 2011.
Khalaf Luhaibi, a local shepherd who led troops to the site, said that ISIS fighters brought captives to the site and shot them or poured oil over them and then set them on fire.
Saad Abbas, a farmer from the area, noted that during the three years that ISIS had control of the town, its fighters had been seen "driving around in cars with their prisoners. They would shoot them and then throw them to the ground or burn their bodies."
The governor of Kirkuk did not say when the authorities would start exhuming the bodies, but he called on the U.N., the Iraqi government and the Commission of Human Rights to conduct DNA tests to identify the bodies in the graves.
Hawija was liberated by Iraqi forces at the beginning of October with the help of Iranian-backed Shia Hashd al-Shaabi militia and Kurdish Peshmerga Forces.
ISIS fighters have been driven by U.S.-backed Iraqi forces from almost all the territory they once held, with some fighting still underway near the western border with Syria.
Several mass graves have been found since the rise of the terror group in Iraq in 2014. A total of 31 mass graves have been found in the northern Iraqi town of Sinjar since 2015.
The graves contained the bodies of at least 1,646 Yazidis, including women and children, Mahma Xelil, the mayor of Sinjar, said in April.
ISIS has reportedly killed thousands of Yazidis, mostly men, and enslaved thousands of girls and women, after taking a control of large areas of Iraq in 2014.
Official government reports have indicated that nearly 6,000 Yazidi men, women and children were abducted in the first days of ISIS attack on Sinjar in August 2014.
An investigation conducted by The Associated Press in 2016 has found that between 5,200 and 15,000 people are buried in 72 mass graves in territories that were once under the control of ISIS.