Two men in Sydney were arrested and charged by Australian counter-terror police on Tuesday, just hours after Prime Minister Tony Abbott warned security officials had detected heightened levels of "terrorist chatter."
A 20-year-old man was arrested in at his home in the suburb of Regent's Park, while a 21-year-old man from Marsfield was arrested in Eastwood, the Australian Federal Police said in a statement.
The 20-year-old is alleged to have been in possession of documents "connected with preparations to facilitate, assist or engage a person to undertake a terrorist act," police said, without explaining the circumstances of the intended act. He faces up to 15-years in prison if found guilty.
The 21-year-old is facing two years in jail, after being charged with breaching the conditions of a court-imposed control order.
"This operation is an example of all agencies recognizing how critical it is to act at an early stage to prevent innocent members of the community being subject to harm," said Deputy Commissioner Michael Phelan.
"We urge members of the public to stay vigilant and to come forward with information they have – your information may be vital to ensuring that police can keep our community safe," Phelan said.
The arrests came on the same day Prime Minister Abbott warned of "heightened terrorist chatter" in the wake of the siege Sydney cafe almost two weeks ago.
"The national security agencies today indicated that there has been a heightened level of terrorist chatter in the aftermath of the Martin Place siege," Abbott told reporters in Sydney earlier on Tuesday, according to Reuters and the Australian Broadcasting Corporation.
"I'm alerting people to the fact that the terror level remains high and at this level an attack is likely," Abbott said.
"That's why it's important that people remain alert and aware, as well as reassured that our police and security agencies are doing everything they humanly can to keep us safe," he said.
Police will have extra officers out over the Christmas period at high-profile sites in Sydney, such as the Opera House and Harbour Bridge, Reuters reported.
Cafe manager Tori Johnson and lawyer Katrina Dawson were killed in the 16-hour siege in the Lindt Cafe in Sydney's central Martin Place square on Dec. 15-16. The gunman, self-styled sheikh Man Horan Monis, was also killed as police stormed the establishment.