A Briton and a Canadian have become the latest Western volunteers to die fighting the Islamic State group alongside Kurdish militants, their families and military authorities confirmed Tuesday.

Ryan Lock, a 20-year-old chef from Chichester, England, and Nazzareno Tassone, a 24-year-old parking officer from Edmonton, Canada, were killed during an ISIS attack on Dec. 21 north of Raqqa, the capital of the terror group’s self-declared caliphate. News of the deaths only recently became public following an announcement by the Kurdish military force they were fighting with the People’s Defense Units (YPG).

Lock was the third Briton to have been killed from among the hundreds of Western volunteers to have taken up arms against IS as part of Kurdish military forces in Syria.

The volunteers have a variety of motivations and backgrounds, but tend to fall into two broad categories, according to a Briton who has fought alongside Kurdish forces and, who, for security reasons goes by the pseudonym Macer Gifford (not to be confused with a British banker of the same name).

Some, Gifford told VICE News, are idealists who have been horrified by reports of IS’s persecution of the Kurds, Yazidis, Christians and other minorities, and are inspired by the Kurds’ fight against the terror group. Gifford, a man with no military background, considers himself among this category.

Others, he said, are former servicemen who have previously battled Islamic extremists in the Middle East and Afghanistan. Angered by the rise of IS since allied forces withdrew from Iraq, they’re motivated to personally take up arms in the absence of major Western ground forces fighting the extremists.

The conflict has also reportedly drawn its share of glory-seekers and eccentric characters, as well as those fleeing their troubles at home.

No military background

According to British media reports, Lock had no prior military experience. He joined the YPG after telling his family he was going to Turkey for a holiday. His father Jon told The Guardian that his son was “a very caring and loving boy who would do anything to help anyone.”

Using their Kurdish noms de guerre, the YPG said in a statement that both men would be “leaders of our struggle and we will remember them in every moment,” while pro-Kurdish Twitter accounts praised them as heroes and martyrs.

Gifford said he never met Lock, but had been trying to make contact with him following a Turkish airstrike on Nov. 24 which killed 12 fighters in his unit, including two foreign volunteers: Michael Israel, an American, and Anton Leschek, a German.

Turkey has been targeting Kurdish fighters as well as IS in its campaign in northern Syria, fearing the establishment of a contiguous Kurdish statelet on its southern border.

Spurred into action by IS atrocities

Like many other volunteers, Gifford was motivated to join the fight after seeing reports of IS’s genocidal rampage against the Yazidis, a persecuted Kurdish religious minority.

Gifford has had two stints in Syria – the first of nearly six months, the second of nearly eight – and is currently raising funds to return with medical equipment. He estimates that perhaps 200 other Westerners have also fought alongside the Kurds – although concrete figures are hard to come by – with many volunteers seeking to join the fight without attracting the attention of authorities at home.

Volunteers usually make contact with the YPG, which actively recruits Westerners, through social media channels such as the Lions of Rojava Facebook page. Once screened for their motivations, they typically join the YPG by flying into northern Iraq, home of the semi-autonomous Kurdistan Regional Government, before being smuggled across the border to Syria.

New arrivals are put through a training course where they are taught how to handle basic Russian weaponry, Kurdish language skills, and the ideological and historical background to the Kurds’ fight. After that, they are assigned to a unit of their choosing, with no more than five foreigners put in any one unit.

Dangerous work

Despite the fact many volunteers lack prior military experience, they are engaged in frontline fighting, Gifford says. “Everyone fights a great deal,” he said. “It’s getting much more intense.” Foreigners comprise only a tiny fraction of a fighting force said to number 50,000, but their presence is highly symbolic.

Gifford says he has noticed a gradual change in the makeup of the international volunteer forces during his stints in Syria – from being predominantly made up of ex-soldiers from English-speaking countries on his first visit, to a much higher number of politically-motivated, left-wing youth – with many now coming from Germany.

Besides the risks on the battlefield – and Westerners are said to be especially prized targets for IS – volunteer fighters can also face potential repercussions when they return home. They are likely to be detained, and could face prosecution if they are suspected of having committed crimes while fighting overseas.

For Gifford and others like him, though, any risks are outweighed by the satisfaction of feeling that they are making a tangible difference.