A Sydney man arrested on Tuesday had documents connected with facilitating a terrorist attack, police allege.

The 20-year-old was arrested at his house in Regent’s Park on Tuesday afternoon.

A 21-year-old Marsfield man was also arrested as part of continuing investigations into the alleged planning of a terrorist attack on Australian soil.

He had breached a control order.

Australian Federal Police deputy commissioner Michael Phelan said there was no specific terrorist threat.

“This is part of ongoing activity,” he said.

The terrorism threat level remains high, meaning a terrorist attack is likely, but not imminent.

He said the group under investigation had no contact with Martin Place siege gunman Man Haron Monis.

The dual arrests come a day after Prime Minister Tony Abbott said there had been a “heightened level of terror chatter” in the aftermath of the Martin Place siege.

The arrests were made as part of Operation Appleby, responsible in September for the largest anti-terrorism raids in Australian history as 800 police took part in pre-dawn raids across Sydney.

Eleven people have been charged since September as part of the operation.

The latest arrests come after police raids last Thursday, Phelan said.

The two men will face Parramatta Local Court on Wednesday.

On Tuesday, Prime Minister Abbott said the nation’s terror threat level had not been lifted but the likelihood of an attack remains high.

Abbott urged the public to go about their lives as normal but report any suspicious activity to the national security hotline.

Police and security agencies will be active and visible through the Christmas holiday period.

“At this level an attack is likely,” the prime minister told reporters in Sydney.

“We don’t know when and how an attack may come, but we do know there are people with the intent and capability to carry out further attacks.”