Four people were injured during Toronto shooting during a rallying rally for the basketball team in Toronto Raptors, police said.
Thousands of sports fans were crammed in the city center at Nathan Phillips Square, sending a lot of hurry to cover.
The event was interrupted shortly after employees calmed the crowd.
Three people were arrested. Authorities have asked the public to send footage to help investigate them.
Police reported that none of the victims had life-threatening injuries although two were seriously injured. They also said they had found two firearms from the scene.
- Toronto celebrates the historic victory of the NBA in Raptors
- Toronto Raptors won the first title
Two million fans were gathered to have gathered in downtown Toronto on Monday for a parade in tribute to the basketball team.
Rapters, the only franchise of the National Basketball Association in Canada, won the finals of the Golden State Warriors Championship last Thursday, the first Canadian team to win the US title. Around mid-afternoon, thousands of gypsies gathered to watch the closing ceremony with players and officials, including Prime Minister Justin Trudo.
Later Mr Trudo wrote that he hoped the "quick recovery" of the wounded.
"We will not allow this act of violence to take away the spirit of today's parade," he said.