An Australian man has died fighting for Kurds against ISIS in Syria after 'stepping on a mine and dying in combat.'

Reece Harding was killed three days ago when a fight broke out during night operations, that led him to step on a mine, killing him instantaneously, according to a post on the Lions of Rojava Facebook page.

Mr Harding's family on the Gold Coast said the 23-year-old left Australia in May and had messaged them that he was duing humanitarian work in the Middle East.

But they feared he was somehow involved in the region's conflict, Keith Harding, Mr Harding's father told the ABC.

Keith Harding said he had been given a message on Monday asking him to call a phone number overseas and that when he did he was told by a voice on the other end of the line that his son had been killed.

'Numbness, disbelief that it's happening,' Mr Harding said of the situation the family now found itself in.

The Lions of Rojava post said five other fighters will injured during the battle that killed Mr Harding.

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An Australian soldier has reportedly died fighting against ISIS in Syria

Reece Harding (back right) allegedly stepped on a mine during night operations

The Lions of Rojava, a band of volunteers that help recruit soldiers to the YPG, posted the news to their Facebook page on Tuesday night.

'Today we pray for our beloved brother who came from far away to do what had to be done!

'Our deep condolences go out to his family, friends and comrades.'

'Today we pray for our beloved brother who came from far away to do what had to be done!' the post read

The Lions of Rojava, a band of volunteers that help recruit soldiers to the YPG, posted the news to their Facebook page on Tuesday night

The messaged was posted to the Lions of Rojava Facebook page on Tuesday night

According to the page, Mr Harding joined the YPG in May and had only been fighting for two months before his death.

'Killed by the cowardly tactic of ISIS,' the Lions of Rojava post reads. 'There are no words that can value the sacrifice, but there are actions that can be taken which can honour him.'

'His whole unit swore revenge for his death and will leave no stone unturned.'

The YPG organise themselves as a basic defence force in Rojava, West Kurdistan. They are known as the People’s Defense Unit.

The Department of Foreign Affairs told Daily Mail Australia it could not immediately comment on the report.

According to the post, five other soldiers were injured during the attack and are currently in hospital

'There are no words that can value the sacrifice, but there are actions that can be taken which can honour him,' the post read

The Lions of Rojava post said Mr Harding 'is the second Australian Lion that gave his life so that the people of Rojava can live their lives in peace.'

Another Australian, Ashley Johnson, was killed in Iraq while fighting with the YPG in Iraq and Syria in February.

The truck he was travelling in reportedly broke down and his group were 'outnumbered and outgunned' by ISIS fighters.

His mother said she only knew of his whereabouts from a text message sent by her son on December 30.