A new United Nations report has tried to count the civilian toll of continuing conflict in Iraq, largely at the hands of Islamic State militants, and the numbers are "staggering."

“Even the obscene casualty figures fail to accurately reflect exactly how terribly civilians are suffering in Iraq,” Zeid Ra’ad Al Hussein, the U.N. High Commissioner for Human Rights, said Jan. 19.

“The figures capture those who were killed or maimed by overt violence, but countless others have died from the lack of access to basic food, water or medical care.”

He said the report showed the sufferings of Iraqi civilians and “starkly illustrates what Iraqi refugees are attempting to escape when they flee to Europe and other regions.”

“This is the horror they face in their homelands.”

Between January 2014 and October 2015, at least 18,802 civilians were killed in Iraq. About half of them died in Baghdad province. Another 36,000 were injured.

The deadliest tactic against civilians has been the use of improvised explosive devices, both in vehicles and in the vests of suicide bombers.

Another 3.2 million people were internally displaced in the 21-month time period measured by the report. The displaced include about 1 million school-aged children.

The figures were recorded by the United Nations Assistance Mission for Iraq and the Office of the United Nations High Commissioner for Human Rights.

“The violence suffered by civilians in Iraq remains staggering,” the report said.

The report noted the Islamic State group’s continued “systemic and widespread violence and abuses” and its systematic persecution of different ethnic and religious communities.

“These acts may, in some instances, amount to war crimes, crimes against humanity, and possibly genocide,” the report continued.

The Islamic State has controlled Mosul, Iraq’s second largest city, since June 2014. It has imposed a rigid version of Islamic law in territory it controls, but its rule also features arbitrary violence.

The U.N. estimates that the group holds about 3,500 slaves. The slaves are mainly women and children of the Yazidi religion. Some of the women are killed for trying to escape or for refusing sexual relations with Islamic State fighters.

The report said that 800 to 900 children in Mosul have been abducted and put through Islamic State religious and military training. There have been accounts of child soldiers who were killed for fleeing fighting on the front lines of Iraq’s Anbar province.

Islamic State courts have sentenced their opponents to punishments including death, stoning, or amputation. Those targeted included people affiliated with the government, doctors, lawyers, journalists, and tribal and religious leaders.

The report said actual casualties could be “much higher than reported” due to difficulties in verifying incidents. This is true particularly of Anbar province, in Iraq's west, much of which is controlled by the Islamic State.

The Islamic State group has targeted ancient sites, churches, mosques, shrines, and tombs it considers to be un-Islamic.

U.N. agencies have also received reports of human rights violations and abuses by pro-government forces. These include unlawful killings, abductions, movement restrictions, and forced evictions. Military airstrikes, shelling and other operations have killed civilians and damaged their property.

At least 2,365 civilians were killed by unknown perpetrators in 2015 from May 1 to October 31.

The U.N. report noted new discoveries of mass graves. Many of the mass graves are recent, while some date to the time of Saddam Hussein.

Jan Kubis, the Special Representative of the U.N. Secretary-General for Iraq, especially denounced the Islamic State group’s treatment of civilians.

“I strongly reiterate my call to all parties to the conflict to ensure the protection of civilians from the effects of violence,” he said.