An estimated 3,500 people, mainly women and children, are being held as slaves in Iraq by Islamic State militants, the United Nations said on Tuesday.
The Islamist group, which also controls large parts of Syria, is responsible for acts that may "amount to war crimes, crimes against humanity, and possibly genocide", particularly against minorities, a report said.
Iraqi security forces and allied groups including Kurdish Peshmerga fighters have also killed and abducted civilians, it said. "Some of these incidents may have been reprisals against persons perceived to support or be associated with ISIL (Islamic State)," it added.
At least 18,802 civilians were killed in violence in Iraq from January 2014 to October 2015, and 36,245 civilians were wounded, the report said, calling the figures "obscene".