An Australian jihadist fighting in Syria has reportedly blown himself up in a suicide bombing near a military airport in the country's east.

For some time now concerns have been growing among the Australian intelligence community about the involvement of Australian jihadists who have travelled to fight in the Syrian conflict.

At least four Australians are known to have been killed in the fighting, but the news of the first Australian to become a suicide bomber is seen as a significant and troubling development.

According to various jihadi websites, at 5:45am on Wednesday the Australian known as Abu Asma al Australi drove a truck loaded with 12 tonnes of explosives into a checkpoint close to the Deir Al Zour military airport.

The website reports say the checkpoint, considered to be the first line of defence for the airport, was completely destroyed and 35 soldiers from the Assad regime were killed.

Abu Asma is described on one website as "our immigrant Lion".

Suicide bombing 'a different level of commitment'

Rodger Shanahan is a former Army officer and an expert in middle eastern terrorism with the Lowy institute.

He says the advent of the first Australian suicide bomber presents a qualitative step up in the level of commitment yet shown by home grown jihadists.

"There's different level of commitment you would think if you've undertaken a suicide attack and ... if there's one there could be more Australian citizens who are that motivated to take their lives in that manner," he said.

Australian intelligence agencies are thought to be tracking about 100 Australians who are currently active in the Syrian conflict, and it is believed that number is growing.

The concern is that some of those individuals will be further radicalised by their experiences overseas and that they could potentially use that experience and training to conduct terrorist operations once they return to Australia.

As Mr Shanahan points out that anyone actively involved in the conflict would have come into contact with terrorist groups.

Australian links to Jabu al Nusra

It is thought that some of the Australians who have been killed have been fighting with Jabu al Nusra, a group with direct links to Al Qaeda.

The area in the north west of Syria where the suicide attack occurred has been a hotspot of jihadist activity.

"There'd be little to no doubt that at least some of these Australian citizens have been coming into contact with hard core jihadists in Syria." Mr Shanahan said.

In its report to Parliament last year ASIO went as far as to warn that Australians fighting in Syria may return to "engage in terrorism".

"Australians who are currently training or fighting overseas may also return to Australia to engage in terrorism, use their knowledge of Australia to help others plan an attack or engage in terrorism overseas," the report said.

Most of the Australians currently involved in the Syrian conflict are thought to be working with the forces opposing the Assad regime.

Although some are actively engaged in the fighting, others are working as volunteers for humanitarian agencies and other Islamic groups.

Gauging who among them could potentially pose a threat on their return to Australia is the big challenge now facing the nation's intelligence agencies.