An investigating court in Hamam al-Alil, south of Mosul, has documented the confessions of eight "Islamic State of Iraq and Syria" (ISIS) elements who had taken part in mass executions in the area during the group's control of Mosul, Iraq’s Supreme Judicial Council spokesman said Wednesday (August 1st).

In al-Khasfa, a mass grave near Hamam al-Alil district, ISIS elements had dumped the bodies of thousands of execution victims at the site in batches.

The site, which is considered to be one of the worst mass graves, is a large, naturally-occurring pit.

"Security forces had arrested eight terrorists who are members of the same family and who commanded ISIS operations in southern Mosul," Abdul Sattar Bayraqdar said in a statement.

The defendants admitted to having taken part in the al-Khasfa carnage, by killing and then throwing security forces personnel and civilians into a large, deep hole in Hamam al-Alil, he said.

"The defendants took part in executing 370 civilians and security forces personnel and in arresting 400 Mosul locals," he said.

"They also admitted to having committed many other crimes," he said, noting that "their confessions were documented and all necessary actions were taken against them according to article 4(1) of the anti-terrorism law".