The U.S. government says it is trying to repatriate the bodies of three American civilians killed while fighting ISIS in Syria.

According to one local Kurdish report, the men were killed over the weekend and identified as Levi Shirley, William Savage, and Jordan MacTaggart. The Washington Post reported Shirley’s death in July, while Denver 7 reported MacTaggart’s earlier this month. Kurdish fighters mourning the men carried signs with the purported photos.

The Americans, whom officials have yet to positively identify, were near the northern Syrian city of Manbij, home to a key ISIS supply route to Turkey, helping the Kurds wrest the city out of the terror group’s hands when they killed.

Earlier this month, Manbij fell out of ISIS control, a major loss for the extremists.

“We have been working to help facilitate the return of the reported remains of private U.S. citizens killed in Syria. We remain in close contact with local authorities and stand ready to provide all appropriate consular assistance. We have no additional information to offer at this time,” John Kirby, U.S. State Department spokesman, said in a statement to The Daily Beast.

The bodies are in Irbil and U.S. officials are seeking to identify and transport them to the United States.

U.S. officials said they do not have estimates of how many such fighters are in the war zone.

Foreign fighters have suited up for battle for and against ISIS in the region. U.S. forces have supported various Kurdish missions across Syria, making the Kurdish People’s Protection Units, or YPG, arguably the most effective on-the-ground fighting force there.

—Nancy A. Youssef