SYDNEY (AFP) - Increasing numbers of young women are altering the profile of Australians joining the Islamic State (IS) group in Iraq and Syria, Attorney-General George Brandis said Saturday, enticed by the "false glamour" of the organisation.

"At an earlier time, perhaps even six months ago, we were concerned almost entirely about young men," Brandis said, according to the Australian Broadcasting Corporation (ABC).

"But a more recent estimate by the national security agencies suggests that a growing number of young women are travelling to participate in that fighting as well."

Brandis said about 90 Australians were now believed to be caught up in the conflict, compared to 70 last year, the ABC reported.

Ever more young people were being "enticed and ensnared here in Australia with the false glamour of participating in the civil war on behalf of ISIL, or Daesh," he added, using alternative acronyms for the group.

"The Australian people should be aware that this is a real and growing problem."

Canberra has passed a law criminalising travel to terror hotspots without good reason, fearful that nationals will pose a risk when they return radicalised. Under new laws, anyone who heads to nominated areas will face up to 10 years in jail.

In December, Senator Brandis accused Islamic militants of using foreign fighters as "cannon fodder" and "propaganda tools" as he revealed 20 Australian nationals had been killed in Syria and Iraq, where IS militants control huge swathes of territory.

The problem was not exclusive to Australia in the region, he said, but one also faced by Indonesia, Thailand and Malaysia.

Top officials from the US-led coalition against the IS group met in London on Thursday for the first talks since the Paris attacks in which 17 people were killed, with the threat posed by homegrown jihadists high on the agenda.

Menawhile Friday a US court jailed a "radicalised" Colorado teenager intercepted by the FBI when she attempted to join her fiance to fight in Syria.