Australia estimates 150 of its citizens are fighting in Syria and Iraq and fears their return

Australia's foreign minister says 150 Australians are fighting with radical militants in Syria and Iraq, raising government fears of a terrorist threat to Australia if the fighters return home.

Foreign Minister Julie Bishop told Australian Broadcasting Corp. on Thursday she has cancelled a number of passports on the advice of security agencies in a bid to reduce the security threat to Australia. She did not say whether the passports were canceled to prevent Australians leaving or returning.

She says Australia will give 5 million Australian dollars ($4.7 million) to the Unites Nations to provide food, medical assistance, tents, access to clean water and hygiene kits to hundreds of thousands pf people fleeing violence in north and northwest Iraq.