A man "inspired by" the Islamic state group was Sunday charged with committing an act of terror over a stabbing attack that Australian police called the "new face of terrorism".
The alleged stabbing by the 22-year-old in Sydney came two days after a teenage boy was charged with making threats at the Sydney Opera House, and both incidents followed an IS call to target high-profile Australian sites.
The man, named in local media as Ihsas Khan, was charged with committing a terrorist act and attempted murder after the alleged attack on a 59-year-old man in the southwest Sydney suburb of Minto Saturday.
"We know that this person has strong extremist beliefs inspired by ISIS (Islamic State)," New South Wales state police Deputy Commissioner Catherine Burn told reporters in Sydney, adding that investigators had seized a "large knife".
Federal Attorney-General George Brandis said investigators established the alleged IS link after seizing material related to the militant group, without giving further details.
The stabbing left the victim, who police believe did not know his attacker, with serious wounds to his hands and body. He remains in hospital in a serious condition.
Burn said that when police were called to a road in Minto where the victim was, the young man allegedly tried to stab officers through a window.
"What made him actually act yesterday, we don't know. But hopefully, our further investigations will uncover that. It was deliberate. It was violent," she added.
"There was clearly some planning and preparation... we will allege down the track that he was going to attack (police) also," she said.
Brandis told reporters in Brisbane Sunday that the victim could have died if locals had not rushed to helped him after he was stabbed, saying they "acted heroically".
The attacker -- who was refused bail after a court appearance Sunday -- was not believed to be connected to any terrorist groups known to police, Burn said, but stressed that the type of threat he posed was a new challenge to authorities.
"This is the new face of terrorism. This is the new face of what we deal with," Burn said.
"There is an individual who, known to police for some matters, decides or for whatever reason, becomes inspired to act; they are able to get some basic capability and act."
The case is due to be heard again in a Sydney court Wednesday.
Prime Minister Malcolm Turnbull last week said the threat of a terror attack in the nation was "real" after IS' call to followers to target prominent Australian locations.
He added Sunday it was not yet known if the Minto incident had been inspired by the IS call, but said there were no plans at this stage to raise the terror threat level, which is currently at "probable".
Officials had said they have stopped 10 terror attacks in Australia in the past two years.
Canberra is set to table two new counter-terrorism bills in parliament this week.
They involve the options of keeping high-risk jihadists in detention beyond the completion of their sentences, and lowering the age threshold to 14 for control orders that aim to prevent an attack by limiting a person's activities.