The driver was then shot by police and taken into custody after jumping out of the vehicle with what turned out to be two fake guns.
The attack is being considered as a possible act of terrorism.
Two police officers said that the attacker was heard yelling, "Allahu Akbar" (Arabic for "God is great"), as he exited the vehicle, SMH reports.
An eyewitness told ABC Channel 7 that he saw a white pick-up truck driving at full speed down a cycle path and hitting a number of people.
He also reported hearing nine or 10 gunshots, BBC reports.