An Australian man reportedly killed fighting with Kurdish forces against the Islamic State terror group in Syria has been praised as a hero by friends and comrades.

Jamie Bright, 45, who was believed to have previously served in the Australian Army, was shot dead in north-east Syria close to the strategically important town of al-Shaddadi last Wednesday, Kurdish groups said.

Tributes to Mr Bright, who joined the Kurdish YPG - or People's Protection Units - in December, poured onto social media after his death was announced by Kurdish forces on Monday.