Calls for justice have continued to grow in Canada amid repeated denials from Iran that its missiles brought down a passenger jet which crashed near Tehran, killing 176 people – most of whom were traveling to Canadian cities.

Canadian officials and members of the country’s transportation safety board are due to travel to Tehran to investigate the crash, although it remained unclear how much access they would be granted to the site.

Crowds gathered across the country to pay tribute to lost friends, co-workers and loved ones on Ukraine International Airlines Flight 752.

Yalda Norouzi was one of hundreds who attended a vigil on Thursday night in northern Toronto – a neighbourhood with so many Iranian-Canadian inhabitants that it is known as “Tehranto”.

Norouzi choked back tears as she recalled her friend Mahdieh Ghassem, who died alongside her two young children, Arnica and Arsan. A week before she left for Iran, Ghassem had won a commission to design a cafe for the popular Canadian coffee chain Tim Hortons.

“They will stay alive in our hearts forever,” she said.

Patty De Frutos, was there to commemorate her co-worker, Alvand Sadeghi, a web developer who was killed in the crash alongside his wife, sister and niece.

“It’s just crazy how destiny works to steal the greatest. We all know he was the best out of all of us,” said De Frutos.

The city’s mayor, John Tory, pledged support for the Iranian community, saying “When one group suffers, we all suffer.”

But as more political and community leaders spoke, mourners grew frustrated.

“We want justice! We want justice!” mourners chanted as others laid candles and flowers at a makeshift memorial.

Earlier on Thursday, Justin Trudeau said that intelligence reports suggested that the plane had been brought down by an Iranian missile. The Canadian prime minister suggested the event may have been unintentional, but called for a thorough investigation.

“Canadians want answers. That means transparency, accountability and justice,” said the prime minister. “This government will not rest until we get that.”

Trudeau declined to lay blame on the US president, Donald Trump, whose decision to order a drone strike on Iran’s most senior general, Qassem Suleimani, stoked rising tensions in the Middle East. Hours before the Kyiv-bound passenger jet came down, Iran had fired a barrage of missiles at US bases in Iraq.

“I think that’s one of the many questions that people will be thinking about and trying to find answers to,” said Trudeau.

Others were less generous in their assessment. One tweet that went viral in Canada read: “The next time some ignorant American tells me, as a Canadian, that I should mind my own business when it comes to their politics, I think it would only be prudent to remind them of #IranPlaneCrash that took 63 Canadian lives due to the actions and fallout of their ‘President’.”

At a press conference on Friday, Ali Abedzadeh, the head of Iran’s Civil Aviation Authority, demanded western governments publish any evidence indicating a missile strike.

“If they have the courage, if they have findings with scientific support, they should show this to the world,” hw said. “One thing I can tell you is the plane was not hit by a missile.”

Legal experts cautioned that even if ironclad evidence can be found, precedent suggests that it will be nearly impossible to hold Iran accountable.

“When you have a missile that attacks a civil airliner, it’s a heinous act of injustice and it’s something that our international treaties are literally not prepared to answer for families,” American aviation lawyer Alisa Brodkowitz told CTV News.

Fifty-seven Canadian citizens died in the crash – a number Canada’s foreign minister revised down from an earlier estimate of at least 63 – making it the country’s worst transport disaster since the 1985 Air India bombing, which killed 268 citizens. That bombing was attributed to Sikh militants, but only one person was ever convicted.