<span style="color: #222222;">The Islamic State group left behind more than 200 mass graves in Iraq containing up to 12,000 victims.</span><br />'' <br />'' <span style="color: #222222;">The United Nations Monday said that this could hold vital evidence of war crimes.</span><br />'' <br />'' <span style="color: #222222;">The UN report said that the dead include women, children, the elderly and disabled, as well as members of Iraq's armed forces and police.</span><br />'' <br />'' <span style="color: #222222;">The grave sites are concentrated in four provinces — Ninewa, Kirkuk, Salah al-Din and Anbar — in the north and western parts of the country, near the border with Syria. </span><br />'' <br />'' <span style="color: #222222;">The UN's human rights office and its mission in Iraq (UNAMI) urged Iraqi authorities to properly preserve and excavate them to provide closure for victims' families.</span><br />''  <br />