Police said officers "initially responded to a report of a auto on fire" in the city centre at around 4:20pm local time, as people began to leave work for the weekend.
"We are now treating this as a terrorism event", said Graham Ashton, police chief commissioner for Victoria state.
The news report above came before police acknowledged that the man was already on the radar of Australian intelligence. At that time other police were starting to arrive.
The incident occurred between Swanson and Russell Streets along the pedestrian strip of Bourke Street mall around 4:20 p.m. local time, according eyewitnesses, in what has been described as a distressing scene.
The attacker had "barbecue-style gas cylinders" inside the auto and set it alight, according to The Guardian.
He died later in hospital.
"We don't believe there is an ongoing threat at this stage, but certainly we are treating it as a terrorism incident".More news: Kim Kardashian, Alyssa Milano Flee Their Homes As California Wildfires Rage
Victoria Police confirmed the man has died and had links to convicted terror plotters.
"There is some minor offending history in relation to cannabis use, theft and driving offences", he said.
Premier Daniel Andrews thanked the strangers who sprang into action "without a moment's hesitation".
The suspect is then shot by police and falls to the ground.
"A small number of people are being treated for stab wounds".
The suspect attacked and stabbed two other people, with one reported to have suffered a head wound.
The body of a victim lay under a sheet on the street.
Police examine a body in Bourke St.in Melbourne, Australia, on November 9, 2018.More news: Second Summit with North Korea's Kim in Early 2019
"Because he was on his stomach, they turned him over to see if he's alright, he was still alive", nearby KFC worker Markel Villasin told AAP.
"He was breathing and he was bleeding out".
Video posted to Twitter and broadcast on television showed the man swinging a knife at two police officers in the city's crowded downtown area, while a vehicle burned in the background.
The officers were immediately confronted by a man brandishing a knife and threatening them.
"I was walking up Bourke St ... and we heard this loud explosion".
Speaking on the Today Show on Saturday morning, he said Shire Ali's vehicle contained gas cylinders and it is believed he meant to cause an explosion.
Counter-terrorism police have been notified, and they are investigating, although there is no immediate indication the incident is terror related.More news: White House accused of using 'doctored' Jim Acosta video