The Iraqi government has started exhuming a mass grave left behind by ISIS in the northwestern Sinjar region in the presence of Nobel Peace Prize laureate Nadia Murad, whose slain relatives are believed to have been buried in the area. The exhumation, which is being carried out with United Nations support, began on Friday in the village of Kocho. Ms Murad's official website said it marks the first exhumation of a mass grave containing the remains of Yazidis, a religious minority targeted for extermination by the extremists. ISIS militants rampaged across Sinjar in 2014, killing Yazidi men and abducting thousands of women and children. Many followers of the minority faith are still missing, after women were forced into sexual slavery and boys were indoctrinated in militant ideology. "I pay my condolence to the Yazidis and the whole humanity. There is not a single Yazidi family that didn't taste the bitterness of this extermination," said Ms Murad. "They all lost their loved ones, their properties and their dreams, and especially in this village," she said. Ms Murad was one of an estimated 3,000 Yazidi women and girls who were kidnapped and sold into sexual slavery. She was raped, beaten and tortured before she managed to escape after three months in captivity. Over 70 mass graves have been discovered in Sinjar since it was liberated from ISIS in November 2015. In November, United Nations investigators said they have verified the location of more than 200 mass grave sites from the time of ISIS rule in northern Iraq, containing the bodies of between 6,000 and 12,000 victims. Nada Selo, an activist from Kocho, lamented the slow pace of efforts to identify and recover victims. "Negligence has been going on for four years and until now. The people were hoping during all this time to see their relatives alive. So honestly, this is a huge disappointment for us as Yazidis, and it is a real tragedy," she said. A statement issued earlier this week by Ms Murad, global Yazidi NGO Yazda and their joint legal counsel Amal Clooney welcomed the process in Kocho. They expressed hope it would be part of a "comprehensive effort which will result in the exhumation of all ISIS mass graves in Sinjar and beyond, the return of victims' remains to their families and the investigation of the relevant crimes, leading to the prosecution of the responsible ISIS militants". The group is on the verge of losing the last area it controls in Syria as US-backed fighters squeeze the extremists in the village of Baghouz near the Iraqi border. Over the past months a number of Yazidi women and children have been freed in eastern Syria.