The UN human rights office says it has received reports of 16 mass graves discovered near Sinjar, the north-western Iraqi town that was liberated from Islamic State last month.

A network of tunnels built by Islamic State has been discovered under the Iraqi town of Sinjar, complete with sleeping quarters, wired with electricity and fortified with sandbags.

Kurdish forces say they have uncovered two mass graves outside Sinjar.

Kurdish fighters are in control of the strategic Iraqi town of Sinjar after taking it from the so-called Islamic State group, witnesses said.

Kurdish peshmerga fighters say they have liberated much of the Iraqi town of Sinjar from the group calling itself Islamic State (ISIL).