Iraq crisis: Acts of inhumanity on unimaginable scale - UN
1 September 2014 Last updated at 17:33 BST
The UN says it has received reports from Iraq that "reveal acts of inhumanity on an unimaginable scale".
Deputy Human Rights Commissioner Flavia Pansieri said Islamic State (IS) was believed to have committed systematic and intentional attacks on civilians.
Ms Pansieri said UN officials continued to gather "strong evidence" that serious violations of international human rights and humanitarian law had been committed in areas under IS control.