Canberra, Dec 9 (IANS): A total of 20 Australians have been killed while being used as "cannon fodder" fighting alongside Islamic State's (IS) Sunni radical militants in Syria and Iraq, Australian Attorney General George Brandis has revealed.

"Nearly one in five Australians that have joined IS groups have been killed, with terrorist organisations using Australians as bombers and propaganda tools," Xinhua reported Tuesday citing Brandis in an interview.

The attorney general said western recruits are being convinced that they are joining a religious crusade, only to be exploited when they arrived in Syria and Iraq.

Brandis' comments came as the government revealed the number of Australians killed has risen over recent weeks, with The Australian daily reporting "five or six" had died in a conflict in Kobane on the Syrian-Turkish border.

"The government is aware of around 20 Australians who have died in the conflict in Syria and Iraq," Brandis said.

It is believed that around 70 Australians remain in the Middle East, fighting for IS groups, while 20 have returned home after traveling to Syria and Iraq.

However, Brandis urged citizens of Australia and other Western nationals to see the reality of what joining IS groups entails.

"Australian youths, and many young men and women from Western countries, are being lured by the falsehood of a noble battle against an oppressive enemy," he said.

"In reality, they are merely taking part in acts of thoughtless violence, in many cases against innocent civilians, on behalf of IS, which is intent on recklessly enslaving, raping and murdering those with a contrary view to their own."