The United Nations said Tuesday more than 200 mass graves have been found in Iraq overwhelmingly containing victims of Islamic State violence.
A report issued by the U.N. human rights office and the U.N. Assistance Mission for Iraq says that based on information from Iraqi authorities and non-governmental organizations, the graves contain between 6,000 and 12,000 bodies.
The U.N. anticipated finding more such graves in the future.
Nearly half were found in Ninewa province where the first mass grave was discovered in late 2014. More were discovered as Iraqi security forces backed by U.S. airstrikes recovered territory from the militant group.
Estimates in Ninewa alone range from 4,000 to as many as 10,500 bodies. Islamic State controlled the area for more than three years and according to the United Nations some of the fiercest fighting of the conflict took place there.
Besides Ninewa, the graves were found in Kirkuk, Salah al-Din and Anbar provinces.
But U.N. human rights spokeswoman Ravina Shamdasani tells VOA this is only a fraction of the number of people who have been killed by IS.
“In the report you will see an estimate of 6,000 to more than 12,000 victims in these mass grave sites. But really, honestly, we have no way of knowing ... We do not even know how many people remain missing in Iraq. Lots of families suffered the loss of their loved ones. But, in order for them to register their loved ones as missing persons, they need to go through many bureaucratic loops in Iraq," Shamdasani said.
So far, the report says, nearly 1,300 bodies have been exhumed from some of the 202 documented graves. The process is complicated, involving the need for careful work to preserve evidence of potential war crimes and to identify the bodies so they can be returned to families.
"In several areas where ISIL remains active — particularly Anbar, Ninewa and Salah al-Din governates — their continued presence may inhibit the ability of investigators to access sites and to carry out their work unhindered," the report says, using an acronym for the militant group.
The world body also expressed safety concerns even in areas where the militants are no longer active, saying that based on past practices homemade bombs are believed to be present at the grave sites.
"The mass grave sites documented in our report are a testament to harrowing human loss, profound suffering and shocking cruelty," said U.N. Special Envoy for Iraq Jan Kubis. "Determining the circumstances surrounding the significant loss of life will be an important step in the mourning process for families and their journey to secure their rights to truth and justice."
The victims include a range of Iraqi civilians as well as members of the Iraqi armed forces and police.
The report calls for the international community to provide any possible technical assistance to investigate the graves and identify remains, and to ensure the Iraqi legal system has the help it needs to carry out any relevant prosecutions.
"The promotion of truth, justice and reparation with guarantees of non-recurrence will be critical to ensuring a full reckoning for ISIL atrocities," the report says. "This in turn could contribute to lasting peace. Victims and their families deserve nothing less."
The United Nations says Iraq should set up a public database of missing persons and create a government body to coordinate with families.
"ISIL's horrific crimes in Iraq have left the headlines but the trauma of the victims' families endures, with thousands of women, men and children still unaccounted for," said U.N. rights chief Michelle Bachelet.
The report says that overall the U.N. has recorded nearly 30,000 civilians killed and 55,000 injured as a result of Islamic State violence, and that those figures should be considered the absolute minimum of what the numbers truly are.
"United Nations human rights reporting during this period found that ISIL had committed systematic and widespread violence and abuses of international human rights law, and violations of international humanitarian law, acts that may amount to war crimes, crimes against humanity, and possible genocide," it says.
Lisa Schlein contributed to this report from Geneva.