Authorities in Iraq’s northern Nineveh province on Sunday launched the first phase of exhuming the Khasfa pit, one of the largest mass graves of Islamic State (ISIS) victims.

Located about 20 kilometers south of Mosul, the Khasfa pit is a natural sinkhole that ISIS used as a dumping site for thousands of victims during its brutal reign. It is estimated to contain the remains of approximately 4,000 people.

Ahmed Qusay al-Asadi, head of the search and rescue team overseeing the operation, told Rudaw that the initial 15-day phase involves collecting evidence, bones, and other remains scattered on the surface. However, the exhumation process faces significant challenges, including unexploded ordnance among the remains and the presence of sulfur water in the area.

“A deep excavation of the grave requires international assistance, engineering teams, and civil defense,” Asadi said, highlighting the need for specialized support.

Nineveh Governor Abdulqadir al-Dakhil described the Khasfa pit as “one of the largest mass graves in human history” and pledged to build a memorial to honor the victims.

ISIS overran large parts of Iraq in 2014, including Mosul, declaring a self-styled caliphate before being territorially defeated in 2017. The extremist group committed widespread atrocities, including genocide, sexual slavery, and mass killings, particularly targeting non-Muslims and Shiite Muslims.

According to Human Rights Watch (HRW), Iraq holds an estimated 400,000 victims in mass graves from ISIS’s reign of terror. The exhumation of the Khasfa pit marks a critical step in uncovering evidence of the group’s crimes and providing closure for grieving families.