Robert Grodt, Nicholas Warden and Luke Rutter were killed fighting IS in Raqqa, Syria
Two Americans and a Briton died fighting with Syrian Kurdish forces battling to oust the Islamic State (IS) group from its Raqqa stronghold.
The three men volunteering with the Kurdish People's Protection Units (YPG) may be the first foreign volunteers to have died since fighting began inside the northern Syrian city.
In a statement on its website on Tuesday, the YPG said Americans Robert Grodt and Nicholas Warden and Briton Luke Rutter were among six "martyrs" on the Raqqa front, without saying exactly where they died.
YPG fighter Demhat who fell a martyr in Raqqa pic.twitter.com/HKLdKCkjkg
— Amed Dicle (@ameddicleT) July 12, 2017
In tweets on Tuesday, the YPG said Rutter and Warden were "martyred in action" on 5 July and Grodt died the next day.
According to a YPG news video, Warden said he was from Buffalo, New York, and had decided to take up arms with the Kurdish militia after the Islamic State-inspired attack in San Bernardino, California. In a Washington Post article, Warden's father, Mark, said Nicholas had “extensive military experience” and two military tours in Afghanistan.
The YPG is a key component of the Syrian Democratic Forces (SDF) alliance of Kurdish and Arab fighters partnering with the US-led coalition against IS.
On 5 November 2016, the SDF launched an offensive dubbed "Wrath of the Euphrates" to retake Raqqa, and after months of fighting in the surrounding area, they entered the city in June.
In a video posted by the YPG on Twitter, Rutter appeared on camera in military fatigues, holding a gun, and said he had received training and Kurdish language lessons since arriving in Syria in March.
"I lied to people I care about to come here," he said.
"Apart from that I don't regret my decision and I hope that you respect it."