An American volunteer fighting with a Kurdish militia was killed Monday in a battle against Islamic State fighters in northern Syria, Kurdish commanders in Syria said.

The American was reported killed north of Raqqa, where U.S.-backed forces are fighting Islamic State as part of an offensive to free the city, the de-facto capital of Islamic State.

A commander with the Kurdish People's Protection Unit (YPG), the main Kurdish armed force in Syria, confirmed the volunteer's death to VOA but gave no other details. He said the YPG will release a detailed statement Tuesday. He spoke on condition of anonymity.

The Kurdish YPG is a key element of the Syrian Democratic Forces (SDF), which has U.S. backing in its fight against IS in northern Syria. The YPG has enlisted the help of an unspecified number of volunteers from abroad in its fight in Syria.

The American's body will be sent to the city of Qamishli and then to the Kurdish region in Iraq before being transported to the United States, according to Mahmoud Bali, a VOA Kurdish service reporter in Syria. He said Kurdish officials are in touch with officials at the U.S. embassy in Baghdad to arrange for the transfer of the body.

The death would mark the fourth time an American died this year fighting with Syrian Kurds against IS.

Levi Shirley of Arvada, Colorado, was killed by a landmine on July 14; Jordan MacTaggart of Castle Rock, Colorado, died Aug. 3; and William Savage of Saint Mary's, Maryland, died Aug. 10 while fighting in a squad that included two Americans and a Swede.