Prime Minister Justin Trudeau paid tribute to the victims of the Danforth Avenue shooting on Friday — helping open the Toronto neighbourhood's signature street festival — while calling for "our best love and our best support" for those killed in that morning's shooting in Fredericton.

"Tonight, we also remember two extraordinary young women, Reese and Julianna, who were out for ice cream ... and got taken from us," Trudeau told the crowd at Taste of the Danforth, recalling Reese Fallon, 18, and Julianna Kozis, 10, who were killed in the Toronto rampage two weeks ago.

"It was a terrible tragedy that affected us all deeply. We hugged our loved ones a little closer that night."

Though sombre, the prime minister spoke passionately about the area's diverse population.

"It's at the essence of what we share with the world loudly and proudly as we gather and celebrate that our differences are a source of strength, never a source of weakness," Trudeau said, drawing cheers from the crowd.

It was a sentiment echoed later by federal NDP Leader Jagmeet Singh, who began by saying acts of violence and tragedy seek to divide.

"One of the strengths of our city, one of the strengths of Canada, is we celebrate our diversity," he said. "In being here today is an act of celebration of that diversity. Please continue to use love to conquer any fear, to conquer any hate, and together we will build a better country."

Toronto Mayor John Tory also spoke at the event and recalled the neighbourhood's resilience after the shooting.

"We didn't wait days. We just waited a few hours, and we came together and showed that solidarity," Tory said. "We're not going to let these things push us off the fact that while we have to grieve and we have to heal, this is the greatest city in the greatest country in the world."

The prime minister was in Greektown — the scene of a deadly shooting rampage last month — to help open the Taste of the Danforth. (John Lesavage/CBC)

The opening of Taste of the Danforth took place the same day that a shooting in Fredericton left four people dead, including two police officers and a local musician. Trudeau also spoke about the "very, very difficult night" in the New Brunswick capital.

"If we could all send them our best love and our best support for our fallen officers who are there protecting us and the people who died in a terrible tragedy," he said.

The opening ceremony also commemorated the Toronto victims with a moment of silence and the singing of Hallelujah by a local musician. First responders and Good Samaritans who helped the victims were also recognized.

Tight security

Police have closed off that section of Danfoth Avenue, a major thoroughfare in Toronto's east end, and security is expected to be tighter than normal.

Organizers say this year's Taste of the Danforth is expected to draw more than a million visitors despite landing so soon after the shooting — a far cry from the 5,000 who attended the first festival 25 years ago.

The festival also includes entertainment, music and dancing.

This year will feature a benefit concert for victims of the shooting. Three memorials that include flowers, cards and other items that sprang up in the aftermath have been relocated to a nearby area.