Kurdish forces besieging an ISIS-held position Tuesday have confirmed that Ashley Johnston, 28, an Australian pictured above at right, was killed fighting with the Kurds, making him apparently the first English-speaking Westerner to die in combat against the Islamic State.

The Guardian reports that Johnston—who had been given the Kurdish name Bagok Serhad by his comrades—was quickly lionized as a martyr by his parent unit in the Kurdish socialist militia:

Johnston, a former army reservist, is believed to the first Westerner killed fighting with a militia, Kurdish People's Protection Units (YPG).

A tribute posted on the Lions of Rojava Facebook page claimed he was killed during an assault around Tuesday on an Islamic State position at a small village near Sinjar in West Kurdistan.

"Throughout his time in Kurdistan, he had a positive impact on my people's lives though his humility and kindness to everyone he met," the post said.

"His squad of eight fighters where in a truck which had broken down and it was critical that they dislodge Isis from their positions so they pushed on fearlessly with little regard for the own safety.

"They where [sic] massively outnumbered and outgunned but fearless in the face of this as they knew another Isis death meant saving the lives of countless civilians. He was a fearless and exceptional soldier as well as a great man.

The Facebook post added: "We took revenge for Heval Bagok, for his family, Australia and the world. His comrades says that it was a revenge for him and his family." That revenge apparently involved the slaughter of dozens of men in the village of Tal Hamis, the ISIS stronghold that Johnston had been helping to assault—and which was apparently "liberated" by his YPG comrades after his death.

According to the Daily Mail, fellow YPG fighter who spoke with Johnston's squadmates told an as-yet unconfirmed story that he died trying to save them from an ISIS attack:

[C]omrades who witnessed Johnston's death said that 'he sacrificed himself for us'.

When asked how, one of the comrades responded with tears in her eyes: 'The panzer that we were inside was encircled by the ISIS-thugs and he jumped out of the panzer to cover us that we could break the encirclement and then he got martyred while trying to cover us and break the siege.'

More pictures and tributes to Johnston rolled in on Twitter under the militia's #YPG hashtag:

The YPG, the militant arm of the Syria-based left-wing Democratic Union Party, has been criticized by Kurds and Americans alike for its socialist aims and its independent operations. But after the Syrian civil war began and the Islamists behind ISIS exploited the battleground power vacuum, the YPG's political arm became known as one of the most important Kurdish opposition parties in Syria, according to the Carnegie Middle East Center. Jordan Matson, a hawkish U.S. Army vet from Wisconsin who joined the YPG late last year, recently estimated on Fox News that 40 or 50 Americans are fighting for the group against ISIS.

It's unknown how many of Johnston's fellow Australians have been recruited in the fight against ISIS, but Australian officials estimated in late 2014 that at least 20 of its citizens had been killed in fighting after joining the Islamic State.