SYDNEY, May 5, 2024 (BSS/AFP) - Western Australian police shot and killed a "radicalised" 16-year-old boy with a knife who had stabbed a man in a Perth car park, police and the state premier said Sunday.

The teenager "rushed" at police who responded by shooting him twice with Tasers before firing a single fatal shot, they said.

"There are indications he had been radicalised online. But I want to reassure the community at this stage it appears he acted solely and alone," Premier Roger Cook said.

Police received a call late on Saturday from a male warning that he was going to commit "acts of violence" but without giving his name or location, the state's police commissioner, Col Blanch, told reporters.

Within minutes, another emergency call alerted police that a "male with a knife was running around the car park" in Willetton, a southern suburb of Perth, he said.

Police body camera images showed the teenager refused officers' demands that he put down the knife, the police chief said.

Officers fired two Tasers at him but "both of them did not have the full desired effect," he said.

"The male continued to advance on the third officer with a firearm who fired a single shot and fatally wounded the male."

The teenager died in hospital later in the night, he said.

- 'Online radicalisation' -

The "middle-aged" man who was stabbed was in a "serious" but stable condition and appeared to be doing well, the police commissioner said.

The boy had "mental issues but also online radicalisation issues", he said.

The attacker had for the past couple of years been part of a "countering violence extremism programme" for people who show signs of "religious or issues-motivated" concerns, he said.

"It is not a criminal based approach but it is a programme to help individuals who are expressing ideologies that are of concern in our community. But they may not be committing any crimes."

Police said they did not know what had triggered the attack.

Despite the rarity of such violent crimes in Australia, the Perth attack comes less than a month after a knife-wielding assailant killed six people in a shopping mall in Sydney.

The mentally ill knifeman, 40-year-old Joel Cauchi, was tracked down, shot and killed by a police inspector.

Cauchi's parents say he was diagnosed with schizophrenia at 17 but stopped taking medication, later leaving their Queensland home and dropping out of treatment.

Two days after the mall attack an Assyrian Christian bishop was brutally stabbed during a live streamed service in western Sydney.

The bishop has since recovered and a 16-year-old suspect has been charged with committing "a terrorist act".