A SYDNEY man charged with committing a terrorist act and attempted murder after allegedly stabbing an unknown man on the street and then trying to knife a police officer was motivated by terror group ISIS.

Prime Minister Malcolm Turnbull has linked the stabbing in Minto with the 9/11 attacks 15 years ago, for the violent Islamist ideology and the heroism trying to tackle it.

He noted the knife attack in Sydney’s west occurred on the eve of the 15th anniversary of the 9/11 attacks on the World Trade Centre and the Pentagon.

“Connecting them both is a violent Islamist ideology,” Mr Turnbull said.

“What also is consistent or common between them is heroism.”

He said while those who died in the 9/11 attacks are mourned, the heroism of those who rushed to the aid of the victims is also honoured.

Likewise in Minto, Mr Turnbull said there was an owner of some premises who sheltered a 59-year-old man who had been assaulted and a bystander who confronted the assailant and managed to keep him at bay until police arrived.

“We honour those heroes of today just as we honour the heroes of 9/11,” he said.

The Joint Counter Terrorism Team — made up of investigators from the NSW and Australian Federal Police — charged Ihsas Khan, 22, this morning after the attack on Wayne Greenhalgh, 59.

“This is the new face of terrorism, this is the new face of what we deal with,” Deputy Police Commissioner Cath Burn said at a press conference this morning.

She said police will be alleging Khan was inspired by ISIS, just one week after the terror group called on lone wolves to attack Australians.

media_camera NSW Police Deputy Commissioner Cath Burn said police believe the attack was inspired by ISIS. Picture: Stephen Cooper

“We know that this person has strong extremist beliefs inspired by ISIS. What made him actually act yesterday, we don’t know,” she said.

Ms Burns said that Khan “may well have” committed the act to lure police to attack them.

She said it was planned and Khan was shouting words at the scene that led bystanders to believe he was committing a terrorism attack.

“We will be alleging this was an act that was inspired ISIS,” she said.

“It was a deliberate act yesterday it resulted in a person receiving extremely serious injuries.

“As we understand of what happened yesterday, there was some degree of planning and preparation to something just before the incident happened.

“We know that this person has strong extremist beliefs inspired by ISIS ... But what made him act yesterday we don’t know.

“It was deliberate, it was violent, his behaviour could have turned worse as well.”

media_camera Ohlfsen Road in Minto where the man was stabbed. Picture: Ian Paterson

She said Khan was not on the terrorism watch list but he was known to police for his “odd” behaviour.

“The 22 year old is somebody who is known to police. He has previously been before the court on a property related charge,” she said.

“He has had a couple of interactions with local police where you might say his behaviour was odd or unusual.

“He was not connected with any known terrorism group or any known persons of interest.

“There may have been some behaviours in the past that might have been concerning behaviours. This is the reality of what we have to face.

“There are going to be people who may have concerning behaviour but you can’t watch everybody all the time.

“There was concerning information about his behaviour but not somebody who we would say is front and centre in our work at the moment.”

media_camera The attack is believed to have taken place in this reserve. Picture: Ian Paterson

She said that although the Khan did not know the man he attacked, he did “form a view of him” for some reason.

“From what we know these two people aren’t known to each other,” she said.

“But for whatever reason, the 22 year old has formed some view about the victim.

“This has resulted in this particular person being the subject of the attack.

“I think although not known to each other, he did form some view about this person.”

She praised members of the community who saw what happened and acted quickly.

Ms Burns said that police had seized a large knife and other items after carrying out search warrants.

“A large knife was found at the location yesterday. Our investigators have conducted a number of search warrants. They have taken material to be further examined,” she said.

The victim of the attack was critical last night, when he underwent surgery for his stab wounds, however his condition has improved slightly this morning, she said.

“From what I understand the victim is a local man. The important thing at the moment is thinking about him,” she said.

She said there was no further threat to the community.