POLICE are raiding homes in Sydney and Melbourne in a counter-terrorism operation involving federal and state officers.
New South Wales police commissioner Ken Moroney has revealed at least six people have been arrested who were "proposing to conduct a terror attack in Australia".
The raids are still being carried out.
Some 400 officers from the Australian Federal Police and the state police forces in New South Wales and Victoria were involved.
The raids are still being carried out.
Mr Moroney said some 15 homes were targeted.
ABC radio said this morning that another nine people were arrested in Victoria in the raids. This has yet to be confirmed.
The swoop follows changes to the law that were rushed through Parliament last week by the Federal Government.
The Prime Minister said the changes were needed to help police avert a terrorist attack.
"A number of search warrants are currently being executed in Sydney and Melbourne as part of a joint operation by the AFP, New South Wales Police and Victoria Police," an AFP spokeswoman said.
"These warrants relate to an ongoing investigation and as a result it would be inappropriate to make any further comment at this time.
"Maintaining operational security is paramount at this stage.
"We can confirm that the ongoing operation relates to the area of counter-terrorism."
The raids follow Prime Minister John Howard's announcement last week of a possible terrorist threat believed to involve potential targets in Sydney and Melbourne.
The Australian reported the threat was linked to a group of Melbourne men who were spotted filming possible targets.
The Government recalled the Senate for a special sitting last week to pass one measure which widened the scope for authorities to arrest terrorist suspects.
Labor, the Australian Democrats and the Australian Greens have accused the government of playing politics with national security and trying to scare Australians.
But Mr Howard last night rejected the claims, saying he announced the changes to anti-terror laws because they were in the national interest.