Police have shot a knife-wielding man after three people were stabbed in Melbourne's Bourke Street.
- A person has died and two others have been injured in the attack
- Witnesses say officers tried to subdue the knifeman after a car burst into flames
- Police shot the knifeman in the chest and he is in a critical condition
One of the stabbing victims died at the scene while two are in hospital.
Police shot the man in the chest after he charged at them with the knife.
He is under guard in hospital in a critical condition.
Witnesses told the ABC a car sped down Bourke Street and crashed after missing a tram.
Video taken by witnesses shows a car on fire in the area and bystanders using a shopping trolley and chair to confront the attacker.
The video shows the man attempting to slash police officers with a large knife before falling to the ground.
One witness said the driver got out of the car and threw "something like a bomb" inside before it erupted into flames.
An eyewitness said someone walked up to the alleged driver and was stabbed directly in the chest.
Witnesses said the man began randomly stabbing people in the street. Two police officers were on the scene quickly and confronted the man.
Victoria Police said a bomb response unit had been called to the area and was currently making the scene safe.
Police said there was no known link to terrorism.
Victoria Police Superintendent David Clayton said when police arrived at the scene they were confronted by a man brandishing a knife and threatening them.
"At the same time, passers-by were calling out that members of the public had been stabbed.
"Police shot the male in the chest and he is now in a critical condition in hospital," Superintendent Clayton said, adding the officers are OK.
In a later statement, police said the man assaulted police, fled on foot, then was shot while lunging at police with the knife.
Officers said they were initially called to a car fire around 4:20pm (AEDT).
External Link: Meegan May tweets: Chaos in #bourkest as a guy seems to have set his car on fire then attacked police with a knife. Police response was swift and overwhelming. I heard at least one gunshot initially.
The Metropolitan Fire Brigade said the fire was contained within 10 minutes.
A caller to ABC Radio Melbourne, Meegan, said she saw the incident from a tram.
She said she saw two policemen trying to subdue a man as a car burned.
"He seemed to be waving something, people around me screamed that he had a knife, but I couldn't see clearly from where I was," she said.
"And then I heard one loud bang. It sounded like a gunshot.
"And someone said they could see someone doing chest compressions on someone as an ambulance started coming up the street."
Another witness, Markel, told ABC Radio Melbourne he ran out of the store he was working in after hearing there was a fire and found himself next to an injured man.
"Turned out there was an old man in front of me, literally by my feet. He was facedown, facedown, and there was a lot of blood," he said.
"I was already stepping on his blood.
"There was a lot of bystanders trying to help him out. They didn't know what to do because obviously in that situation it is pretty crazy."
Markel said bystanders were yelling out "just shoot him, just shoot him," while police officers were trying to disarm the attacker.
Police are asking members of the public to avoid the area.
"Anyone with information or who witnessed the incident is asked to go to Melbourne West Police Station to make a statement," a police statement said.
Trams are not running along Bourke Street or Swanston Street in either direction.
Premier Daniel Andrews tweeted, urging people to avoid the area and follow the instructions of emergency services personnel.
Opposition Leader Matthew Guy tweeted:
"Today, more than ever, we offer our thanks to Police and first responders for the unbelievable work they do for all of us."