U.S. defense officials said one American soldier was killed Thursday morning as Special Forces and Iraqi troops raided an ISIS-run prison in northern Iraq, the first U.S. soldier killed in action in Iraq since 2011.

An estimated 70 Kurdish hostages were freed during the operation, which The New York Times reports was the first commando operation against ISIS in Iraq.

CBS reports “a number of ISIS militants” may have been captured in the raid, which took place near the city of Hawija, in Kirkuk.

“[U.S. troops] cut off roads and raided the place successfully,” Najmaldin Karim, the governor of Kirkuk Province, told the NYT. “They were able to take people with them.”

Back in February, ISIS posted propaganda videos that allegedly showed captured Kurdish Peshmerga fighters—who have been U.S. allies in Iraq and Syria—being carried through Hawija in cages:

It’s not clear whether these were the same hostages released during Thursday’s mission.

Update: The soldier killed in action has been identified as Master Sergeant Joshua Wheeler, 39. He was a Delta Force commando from Roland, Oklahoma.

[Photo of a Kurdish Peshmerga fighter via AP Images]