Two American Special Operations advisors to the Iraqi Special Forces were killed during an operation against Islamic State (ISIS) remnants in the Qarachogh mountain region of northern Iraq on Sunday, the U.S.-led coalition released in a statement Monday.

“Two U.S. service members were killed by the enemy while advising and accompanying Iraqi Special Forces during a mission to eliminate an ISIS terrorist stronghold in a mountainous area of north-central Iraq,” according to a statement from the Combined Joint Task Force — Operation Inherent Resolve.

The names of the two troops killed are being withheld pending notification of their next of kin. SOFREP has learned that the two Americans were Marine Raiders from the Marine Forces Special Operations Command (MARSOC).

The operation took place in the Qarachogh Mountains, outside of the town of Makhmour. Rudaw, the Kurdish media network, was the first to report on Sunday that coalition aircraft provided cover along with attack helicopters, while soldiers fast-roped onto the objective.

Iraqi military sources claim that 25 ISIS terrorists were killed and nine tunnels destroyed in the operation.

The area surrounding this region has been constantly a source of contention between the Iraqi government and the semi-autonomous Kurds. Because of this, it allowed for a power vacuum to be created; a vacuum that ISIS used to make inroads. Located just 60 kilometers southwest of Erbil, ISIS fighters have used Qarachogh mountain as a safe haven since they were routed out of Iraq and Syria in 2017.

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In 2014, the Islamic State captured vast areas of both Syria and Iraq and created a “caliphate.” It has since been pushed out of nearly all of them. However, small cells remain behind and wreak terror on the local population. They’ve also attacked Iraqi government forces and militias. 

The Pentagon’s Inspector General published a report that stated that ISIS remains a threat in the area. 

“ISIS maintained both freedom of movement and the ability to hide and transport fighters and materiel in rural areas where [the Iraqi Security Forces] presence is less intense and ISIS can more easily avoid detection and capture,” the report said.

“ISIS retains enough manpower and planning capabilities to conduct regular small-scale attacks or ambushes against the ISF [Iraqi Security Forces], the PMF [Popular Mobilization Forces], or local civilians accused of aiding the ISF or informing on ISIS activities.”

Joint counter-ISIS operations between Iraq and the U.S. were restarted in mid-January after they were temporarily suspended because of a drone strike that killed Major General Qassem Soleimani, the commanding general of Iran’s Quds Force, in Iraq. That resulted in the U.S. Embassy in Iraq being attacked and a call from some Iraqi lawmakers for the United States to withdraw from the country.