The teenager “rushed” at police after wounding someone and was fatally shot by an officer, premier Roger Cook told a news conference.

“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.”

Police had received a call late last night 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.