The video was reportedly captured by a person in a nearby office and uploaded by a friend on social media site Twitter.
In another video of the same incident - this time from the protesters' view point - protesters can be heard cheering on the driver of the vehicle; saying: "Yeah, bro!"
The incident came after a pre-planned operation saw hundreds of police staff swarming Parliament's grounds to remove anti-mandate protesters who had been camped there for 23 days.
A total of seven police staff needed hospital treatment as a result, authorities said in a statement.
"They have a range of minor and serious but non-life-threatening injuries," police said.
"Some injuries were lacerations caused by objects thrown at them. These included bricks and paving stones taken from the nearby streets, rocks, traffic cones, poles and wood from pallets.
"Staff were also showered with paint, petrol and water from a high-powered fire hose."