Australia said Tuesday it will introduce new laws this week to strip dual nationals linked to terrorism of their citizenship, but backed away from putting the power in the hands of a single minister.

The legislation will see the Citizenship Act -- which currently stipulates a person ceases to be a national if they serve in the armed forces of a country at war with Australia -- expanded to include people who "fight against us in a terrorist group".

There are currently 20 such groups on Canberra's list of terrorist organisations.

"If people have become terrorists, our intention as far as we humanly can is to stop them from coming back," Prime Minister Tony Abbott told reporters.

"Today's announcement is all about... giving the government additional mechanisms for stopping hardened terrorists returning to Australia."

The announcement came as the government sought to confirm reports that two high-profile Australians fighting with the Islamic State group, Khaled Sharrouf and Mohamed Elomar, were killed in the Iraqi city of Mosul in the past week.

Canberra has not said if they are dual nationals.

The government has been increasingly worried about foreign fighters returning home, with parliament passing a slew of national security laws since Canberra raised the national threat alert to high in September.

Federal police have also carried out counter-terrorism raids in the country.

- New Laws -

The new laws announced Tuesday will see dual nationals lose their citizenship through "renunciation by conduct" and "revocation by conviction", said Abbott, which means loss of citizenship would occur automatically under the expanded act.

In essence, he continued, citizenship could be stripped from foreign fighters or people who "engage in terrorism-related conduct inspired by terrorist groups" in Australia or overseas, if they are dual nationals.

The legislation, when tabled in parliament on Wednesday, would specify what conduct is covered, but Abbott added that it broadly meant "serious involvement with a terrorist group".

Canberra had previously mulled allowing the immigration minister the right to decide who should lose their citizenship, but he will now only inform them of their fate.

"It will be the operation of the law that actually strips people of their citizenship rather than the ministerial decision as such," Abbott said.

"If, however, the person so affected believes that there is some problem, this matter will be legally reviewable."

The laws will be examined by a parliamentary committee on intelligence and security. The Labor opposition is generally supportive of the changes.

About half of the 120 Australians that the government believes are fighting with jihadist groups in the Middle East are dual nationals, the prime minister said.

The intelligence and security committee would also look into whether the legislation, if passed, could be retrospectively applied to take into account dual nationals currently in jail on terrorism convictions.

A separate review is looking into how the government would deal with second-generation Australians with sole nationality who are suspected of terrorism links.

Any moves to strip such Australians of their citizenship could render them stateless and see the country violate the UN Convention on the Reduction of Statelessness, of which it is a signatory.

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