The United Nations has said at least 5,576 civilians have been killed by violence in Iraq this year.
At least 11,665 have been wounded since January, when Sunni fighters from the group calling itself the Islamic State, overran the city of Fallujah in the western province of Anbar, the UN said on Friday.
Last month, fighters seized swaths of northern Iraq, including the area's largest city, Mosul. Of the 2,400 people killed in June, 1,531 were civilians, the UN said earlier this month.
The report documents what it calls "systematic and egregious violations" of international law by the group previously known as the Islamic State in Iraq and the Levant.
The UN found the group had executed civilians, committed sexual violence against women and girls, carried out kidnappings and targeted assassinations of political, community, and religious leaders and killed children, among other violations.
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The report also details violations committed by government forces and affiliated groups, citing "summary executions / extrajudicial killings of prisoners", which it said may constitute a war crime.
The UN noted that the "deteriorating security situation" had limited its ability to directly monitor and verify incidents.
More than 1.2 million people had been displaced since violence escalated last month, according to the report.