Three Sydney men have been arrested over an alleged IS-inspired plot to attack a variety of targets in Australia including embassies and court buildings.
Federal and NSW counter-terrorism police raided six properties in Sydney's west on Tuesday morning and arrested the three men aged 20, 23 and 30.
Authorities say the younger men were members of IS and the plot - which was in the "early stages" of planning - targeted police stations, defence establishments, embassies, councils, courts and churches.
AFP Assistant Commissioner Ian McCartney said the 20-year-old man from Greenacre, believed to be Isaak el Matari, had been monitored for the past 12 months since returning to Australia from Lebanon.
He was known to Lebanese authorities.
The 23-year-old from Toongabbie was allegedly "prominent in the global online extremist community".
"There are still those people in the community who wish to do us harm," Mr McCartney told reporters in Sydney.
"They wish to do the community of Australia harm. I want to say (however) they don't represent the Islamic faith."
Tuesday's raids were conducted in Canada Bay, Chester Hill, Greenacre, Green Valley, Ingleburn and Toongabbie.
News footage showed officers removing boxes of evidence from houses.
The three men will likely be charged later on Tuesday.
Mr el Matari is expected to be charged with preparing for a terrorist act and preparing to enter a foreign country for the purpose of engaging in hostile activities. He could be jailed for life if found guilty.
The 23-year-old is expected to be charged with being a member of a terrorist organisation. He could be jailed for 10 years.
The 30-year-old - an associate of the other men - is expected to be charged with obtaining financial benefit by deception through fraudulently claiming unemployment benefits. He too faces 10 years behind bars.
"There is no immediate threat to the safety of the community as a result of this activity," a NSW Police spokeswoman said earlier on Tuesday.
Anti-terror operation shows need for new federal laws: Dutton
Home Affairs Minister Peter Dutton says the anti-terror operation shows the need for new federal laws to temporarily exclude dangerous Australians.
The coalition party room meeting in Canberra on Tuesday gave the green light for Mr Dutton to bring new national security laws to parliament this Thursday.
"This is incredibly important because it will be alleged in relation to one of the individuals arrested and charged today that he returned from overseas as an Australian citizen," Mr Dutton told reporters in Canberra.
"This threat is not diminished, it's not going away ... particularly when we've got Australians overseas in a theatre of war being trained by Islamic State or inspired online."
Mr Dutton said the laws would allow authorities "more time to manage individuals".
"When some people come back, it is very difficult to gather the evidence that would be admissible in a court of law in Australia to convict that person beyond reasonable doubt so we need to make sure that we've got every tool available to us to keep Australia safe."
He called on Labor to offer bipartisan support for the bill.
At an inquiry into the laws earlier this year the Law Council of Australia and the Australian Human Rights Commission said it should not be passed in its current form.
"This is a dog's breakfast," Law Council president Arthur Moses said.
The legislation went against two High Court rulings that the minister could not stop citizens from returning to Australia, he said, and it should instead follow the UK model where a court has to make the exclusion order, the Law Council said.
The UK example offered greater transparency and better protections both for the minister and the person affected by the order.
Home Affairs says there are about 100 Australians still actively involved in the Syria and Iraq conflicts who may pose a threat when they return home.
