The attack, which may be qualified as an act of genocide, in which Yazidis were brutally murdered reportedly took place exactly three months ago. Girls who escaped the killing described the horrific event to investigators.
“We keep finding evidence of their actions, and this needs to be documented and recorded,” Qassim Simo, the head of the local intelligence department, told Al Jazeera.
However, some of the evidence could have been lost due to heavy shelling from Peshmerga forces and US-led coalition airstrikes. Another obstacle for a full-scale investigation of the alleged Yazidi genocide present bombs and landmines, left by ISIL everywhere across the area.
Another mass grave, containing bodies of almost 60 Yazidi men, women and children was discovered west of Sinjar on Sunday, according to AFP.
These are not the first mass graves discovered in Iraqi Kurdistan in areas freed from ISIL.
Local officials said there are hundreds of mass graves expected to be discovered across Sinjar Mountains. According to UN estimates, at least 5,000 children, women and men have been killed by ISIL militants since summer 2014 offensive, when ISIL captured the region, systematically enslaving, raping and killing thousands of local residents.
Yazidis practice an ancient syncretic religion linked to Zoroastrianism, which Islamists regard a heresy.
On Friday, the Kurdistan Region Security Council announced that the Peshmerga reclaimed Sinjar, which was held by the Islamic State for more than a year.