Emergency services rushed to the scene where a shooting had earlier interrupted the Toronto Raptors victory parade on Monday.
Police cars, ambulances and fire engines were filmed moving through streets thronging with people. Riot police and police on horseback were deployed to control crowds.
Four people were hurt in the incident, although the injuries are not thought to be life threatening.
Toronto police said that three suspects were arrested and investigations were ongoing. No motive has been established so far.
The shots only briefly interrupted victory speeches at Nathan Phillips Square, the parade's final destination.
An estimated two million people, including Canadian Prime Minister Justin Trudeau, were on the streets of Toronto to celebrate the Raptors NBA Finals win.