TORONTO — Hours of anticipation gave way to unbridled euphoria as a sea of Raptors fans greeted the newly crowned NBA champions with cheers, whistles and chants on Monday, but elation quickly turned to fear when gunshots interrupted the celebration in downtown Toronto.

Moments after the team emerged on stage during a rally at the end of a victory parade, the sound of gunfire sent dozens of panicked supporters running from the one end of Nathan Phillips Square, grabbing friends and children as they fled.

The festivities were briefly suspended as one of the hosts alerted the masses, most of whom had been there since the morning, that there was an emergency. Organizers urged the public to stay calm and the event resumed shortly afterwards.

Police later said four people had suffered injuries related to the shooting. Three people were arrested and two firearms were recovered, they said.

Some fans said they feared for their lives and remained shaken even after the situation returned to normal. Others said the shooting, though frightening, should not mar the festivities.

"It's so horrible that that happened but we are united as a city and that shouldn't define who we are or what today was about," said Ahilan Sivakumar, 19.

Several had huddled near pillars in Nathan Phillips Square even as the team and several dignitaries — including Prime Minister Justin Trudeau and Ontario Premier Doug Ford — remained on stage during the rally. Others dashed into a nearby hotel or leapt into bushes to get out of the way. The ceremony wrapped up a short time later.

Andrew Singh said he heard what appeared to be gunshots before people started scrambling.

"We just saw the girl drop to the floor and the guy running off," the 29-year-old said. " All I heard was bop bop bop."

The rally — and the shooting that interrupted it — capped off a day that saw fans dressed in red and black — the Raptors' colours — take over swaths of the city's downtown. City officials said more than a million people were gathered in and around the area.

Supporters had spent several hours at Nathan Phillips Square waiting for the team. The site was quickly overflowing with fans of all ages and police worked to stop more people from entering the area.

The victory parade, which included five open top double-decker buses carrying the players, slowed to a crawl and at times halted completely due to the crush of people along the route.

Members of the Raptors smiled from the buses, some splashing the crowds with champagne. At one point, Kyle Lowry, the longest-serving member of team, was seen hoisting the Larry O'Brien Championship Trophy while some of his teammates smoked cigars.

"This is unbelievable," said Lowry, who later carried the trophy on stage for the rally.

Kawhi Leonard, one of the team's star players, also marvelled at the fan response. "It's been amazing," he said. "Thank you Toronto, thank you Canada for the support, we did it," he said.

Canadian rapper Drake, one the team's most famous supporters, was alongside players during the parade, smiling broadly. He later took to the stage at the rally, urging fans to take in the moment.

Construction workers watched the festivities from scaffolding along the route, and as traffic ground to a standstill on a nearby thoroughfare, some motorists left their vehicles to peer at the activity.

Many fans said they decided not to go to school or work so they could attend the celebration.

Cypher Sabanal, 15, said his mom let him skip school to attend the parade.

"I actually have exams this week but being here is worth it," he said, adding that he's been a Raptors fan his whole life.

For several people, the parade marked a historic moment.

"I haven't seen anything like this happen in the city before so it's great to be a part of it," said 28-year-old RJ Salvador.

Fans held up signs and enlarged heads of their basketball idols like Leonard and Fred VanVleet. Several hoisted signs urging Leonard, who will become a free agent in the off-season, to stick with the team he helped rise to the top.

Mayor John Tory declared Monday "We The North Day" in Toronto, after the NBA champions' slogan. The mayor, dressed in his now-famous black-and-gold Raptors blazer, urged all fans to celebrate the team's historic win.

Many who couldn't make it downtown watched the festivities from afar. Several schools in the city showed the parade in classrooms and some held their own victory marches for students.

"Today’s history lesson in room 137! Watching the @Raptors first victory parade! I told them that one day their children will ask about where they were during the parade and to tell them that the awesome Miss Latchford put the parade on for them in class!," one educational assistant tweeted.

The Raptors' championship win last week came in Game 6 of a rollercoaster series that captured national attention. On Monday, the Golden State Warriors took out a full-page advertisement in the Toronto Star newspaper, congratulating their rivals for taking the title.

The last time the city held a sports celebration of this magnitude was after the Toronto Blue Jays won the World Series in 1993. That parade saw fans climbing trees and statues on city streets to catch a glimpse of a team that included Joe Carter and Roberto Alomar.

— with files from Lori Ewing, Gregory Strong and Colin Perkel.