Witnesses say police chased a man carrying a weapon down Bourke St following a crash that saw a car burst into flames.

One witness said two officers trying to apprehend man and he produced a knife and tried to “stab them.”

This is impressive:

Two bystanders stepped in to surround the armed man, including one who used his trolley as a weapon.

The witness then picked up a rubber weight on the ground to help the officers under siege.

Three people have been taken to hospital. A witness reported an apparently serious attack injury:

He said there was a person covered in blood near the car receiving first aid.

The witness said the injured person was either being given CPR or had a possible throat wound.

More to come.

UPDATE. One victim of the attack is now reported to have died at the scene.

UPDATE II:

Reports on 3AW Radio indicate that witnesses saw the man driving the vehicle “throw something into the back”, which then ignited.

UPDATE III. All hail the trolley man:

One heroic eyewitness rushes at the attacker with a shopping trolley, briefly slowing him down and falling in the process.

Meanwhile another bystander closes in while holding a chair from a nearby cafe.

The first man was not deterred, however. He sprung back into action and charged back towards the attacker, shoving the trolley back in his direction as police opened fire.

Great work, sir.