The men were arrested overnight as part of an ongoing counterterrorism operation and will appear in court on Wednesday, police in Sydney said.

Sulayman Khalid, 20, was charged with possession of documents designed to facilitate a terrorist attack, while an unnamed 21-year-old was charged with breaching a control order.

The arrests are related to a series of raids in September across Sydney and Brisbane, with police saying then that they had uncovered a plot to "commit violent acts" in Australia, including a plan to behead a member of the public.

But Australian Federal Police Deputy Commissioner Michael Phelan said there was no specific terrorist threat related to the latest arrests.

"There is nothing that indicates at all that (there were) any specific targets or time frame in relation to this particular incident," Phelan said, adding, "The documents talked a little bit about potential government targets."

"It is a group of people here in Sydney that we've been actively monitoring for a long period of time now and any action they take, we want to try and get ahead of them," the police official said.

Phelan said police had been monitoring a group of 15 to 20 people, and had charged 11 since the raids in September, some for "serious terrorism offences." He said their ideology is linked to the "Islamic State" movement.

Lindt cafe siege

The arrests come during the aftermath of a fatal siege in Sydney's financial hub last week.

A self-styled cleric, Man Haron Monis took 17 people hostage inside the Lindt cafe in central Sydney's Martin Place on the morning of December 15. The siege ended 16 hours later in gunfire as police rushed in to free those inside. Two hostages were killed - 38-year-old barrister and mother of three Katrina Dawson, and the cafe's 34-year-old manager Tori Johnson - along with Monis.

On Tuesday, Australian Prime Minister Tony Abbott warned of "increased chatter" among terror sympathizers. Australia has not officially labeled the Sydney siege as a terrorist attack.

Canberra raised the country's terror warning level to 'high' in September, in response to a perceived domestic threat posed by supporters of the Islamic State.

jr/jm (AP, AFP, dpa)