More than 200 graves containing the corpses of thousands of victims have been discovered in areas formerly controlled by the Islamic State group, a UN report said, according to Al Jazeera.
The report by the UN Human Rights Office and the UN Assistance Mission documented the existence of 202 mass grave sites in the northern and western Iraqi governorates of Nineveh, Kirkuk, Salah al-Din and Anbar.
The dead include women, children, the elderly and disabled, as well as members of Iraq's armed forces and police, the report said.
These deaths occurred in what the United Nations has called a systematic and widespread campaign of violence, "which may amount to war crimes, crimes against humanity and genocide".
It may be difficult to specify the exact number of people in the graves, with the smallest site in west Mosul believed to contain eight bodies while the biggest in the Khasfa sinkhole south of Mosul is believed to contain thousands of corpses.
The UN has said previously that almost 33,000 civilians were killed by the group in Iraq, with more than 55,000 injured.
The report notes that the sites could provide critical forensic material that can lead to the identification of victims and help understand the scale of crimes committed by IS.
"Evidence gathered from these sites will be central to ensuring credible investigations, prosecution and convictions in accordance with international due process standards," the report said.
"Meaningful truth and justice requires the appropriate preservation, excavation and exhumation of mass grave sites and the identification of the remains of the many victims and their return to the families," the report said.
In 2014, the armed group captured vast swaths of Iraqi territory, including the country's second largest city of Mosul.
IS had entrenched itself in these areas until their defeat in December 2017 by Iraqi forces supported by a US-led coalition.
During its three-year rule, the group harassed local residents, conducting well-publicised executions of people targeted for their perceived opposition, government ties, sexual orientation and more.