In a shocking scene caught on video, a taxi driver was dragged more than 20 metres in downtown Toronto while confronting a driver working for the ride-hailing service Uber.

The incident happened as cab drivers across the city were converging on city hall to protest Uber, which they say is flouting city bylaws and cutting into their bottom line.

The cabbie, who identified himself to CBC News as a taxi driver with 22 years of experience, confronted the driver of a white Honda Civic on Bay Street near Queen Street West, close to city hall.

An Uber Canada spokesperson called the incident "frightening," and said the company has spoken with both the driver and passenger who were in the Honda. Neither was harmed.

The confrontation begins when the taxi driver pounds on the window of the Honda as it's stopped near a traffic light.

"This is UberX," he says, with news cameras rolling.

The man then tries to open the driver's side door of the car while pounding the window. The car accelerates and drags the man before eventually coming to a stop at another red light.

The Honda drives through the intersection, leaving the cab driver standing in the middle of traffic.

The cab driver appears unhurt and, gasping for breath, spoke with reporters seconds after the incident.

"We are trying to get a point across, that's what we're trying to do," he said.

New video emerges

Albert Kleyen, the UberX passenger who was inside the vehicle, captured video of the confrontational incident, which he posted on Facebook. 0:34

Albert Kleyen, the Uber passenger who was inside the vehicle, also captured video of the incident, which he posted on Facebook.

From inside the car, you can see the taxi cab driver speaking to reporters.

"This is crazy," Kleyen says on the video.

Moments later, you can hear the taxi driver pound on the door, and there are more bumping noises as the UberX driver tries to escape the situation and the taxi driver clings to the side of the car.

"Jesus Christ," Kleyen says.

Citywide protest underway

Sajid Mugha, of the iTaxi Workers Association, told CBC News the taxi driver's behaviour is "unacceptable," but said the video "illustrates the frustration of our drivers."

"If someone was stealing your food, how would you feel?" Mugha said.

Mugha said the taxi group is attempting to contact the driver to speak with him, and in no way endorses this behaviour.

Uber Canada also condemned the altercation.

"We were alarmed to see this act of taxi aggression against Toronto Uber users," said Uber's Susie Heath in an email to CBC News.

The company also criticized the citywide taxi protest, saying: "rather than blocking the roads and causing fear and frustration, we believe that open collaboration is the best path forward."

Mayor asks cab drivers to 'stand down'

Mayor John Tory, speaking with reporters at city hall, called the incident captured on video "profoundly unacceptable" and asked cab drivers to stop their protest before the afternoon commute.

"I am specifically requesting cab drivers to stand down," Tory said.

He also warned taxi drivers they could be driving people toward Uber instead of away from it. Still, the mayor said, he understands cab drivers are struggling and he is keeping the pressure on staff who are working to modernize the city's ground transportation bylaws.

In September, Toronto city council asked staff to develop new rules to accommodate Uber in its taxi and limousine bylaws, with an added request that Uber cease operations until those rules are established.

But Uber has continued to operate, frustrating traditional cabbies.

In Wednesday's protest, cabs from across the city gathered at four marshalling points before heading toward downtown. They slowed traffic on highways outside the city, and stopped traffic outside Queen's Park before heading to city hall.