(JTA) — An American man who volunteered to fight with Syrian Kurds against the Islamic State was killed in the fighting. Levi Jonathan Shirley, 24, died on July 14, the Kurdish Peoples’ Protection Units, or YPG, said in a statement July 21, according to Reuters. He reportedly was killed by a land mine in northern Syria.

Despite his Jewish-sounding name, Shirley, who lived in Colorado, was not Jewish, his mother, Susan, told JTA in an email. Susan Shirley said that she is “almost certain” that her mother’s grandparents were Jewish by birth, “but at a time when a person who had converted to German Baptist would not necessarily say they were Jewish.” She added that she has always felt a “strong pull toward Israel and Jewish traditions.”

Levi Jonathan Shirley, who was known as Jack by his family, adopted the Kurdish name Agir Servan, which reportedly means fire. He left for Syria in February 2015 to fight the Islamic State, returned in June 2015, then went back again in January. The Jerusalem Post quoted Jonathan Botan, a Jewish-American man in Syria fighting the Islamic State, as saying four or five Jews have joined YPG. Dozens of foreign volunteers have traveled to Syria to fight against Daesh, an acronym in Arabic for Islamic State.

CAP: Levi Jonathan Shirley