One person has been stabbed to death, two have been injured, and another man has been shot by police in terrifying scenes on Melbourne's Bourke Street on Friday.
One of them has succumbed to injuries, police said.
Just after 5.20pm (local time), a body was seen lying under a white sheet on Bourke Street, near the entrance to Russell Place.
As police officers reached the scene they were confronted by a knife-wielding man who tried to attack them. We'll keep an open mind as to whether there's any link.
Videos shared on social media show a man attacking two police officers with an object, before he is subdued by police.
A man, believed to be the driver, stabbed three people and was then shot by police.
He has been taken to hospital in a critical condition.
The condition of the other two victims was not yet known.
One of the victims has died, while the others have been taken to hospital.
Earlier, Ambulance Victoria said they had assessed three people at the scene.More news: Lakers validate LeBron's proclamations of progress with win at Portland
The exact circumstances are yet to be determined at this stage.
Mr Hair said two civilians became involved as well as two police, trying to stop the man from his attack.
The man allegedly set his auto on fire and stabbed a number of people this afternoon before being shot.
A vehicle is on fire as police confront the man in Bourke Street, Melbourne, on Friday afternoon.
A Melbourne-based reporter tweeted that nearby buildings were placed on lockdown by the police following the incident.
Her immediate thought was, "Oh no, not another Bourke Street incident", she said. Police response was swift and overwhelming.
The street where the vehicle caught fire is the same one when in January 2017 a fatal but not terror-related incident when a man plowed his auto in to pedestrians at a high speed, killing six people and woulding about 30.
"I really wanted to help but I was in shock, I didn't know what to do".
The Victorian premier, Daniel Andrews, urged people to avoid the area. Fully engulfed. Multiple loud bangs."This incident in Bourke Street comes on the second day of the highly-publicised murder trial of James Gargasoulas, who allegedly drove through Bourke Street Mall on January 20, 2017, killing six people and injuring 27 others".