Melbourne: Australia today said about 150 of its nationals have been or are currently fighting with radical militants in Iraq and Syria, warning that such people could pose a security risk if they were allowed to return home.
"About 150 Australians have been or are still fighting with opposition groups in Syria and beyond," Foreign Minister Julie Bishop said.
Al-Qaeda splinter group the Islamic State of Iraq and Syria (ISIS) has rampaged across Iraq in the past two weeks and are currently threatening to overrun capital Baghdad. It wants to create an extremist caliphate across the Middle East.
"In Syria it seems that over a period of time they (Australians fighting alongside extremists) have moved from supporting the more moderate opposition groups to the extreme, and that includes this brutal extremist group ISIS," Bishop told Australian Broadcasting Corp.
"We are concerned that Australians are working with them, being radicalised, learning the terrorist trade and if they come back to Australia of course it poses a threat."
She said she has cancelled several passports on advice from intelligence agencies, without elaborating whether they were canceled to prevent people leaving or returning home.
Immigration Minister Scott Morrison had said the government is looking at its options in relation to cancelling the visas or revoking citizenship for dual nationals who have fought alongside extremists.
Bishop welcomed the Iraqi prime minister`s call for national unity, saying "we need to see a political solution because a military solution could be catastrophic."
She said neither the US nor Iraq had yet asked for Australia`s help in the latest crisis.
Australia sent 2,000 troops to support US and British forces in the 2003 Iraq invasion.