Canadian Prime Minister Justin Trudeau has told a vigil for some of those killed in an Iranian plane disaster that he would “pursue justice and accountability” for what happened.

Iran says it mistakenly shot down a Ukrainian airliner on Wednesday, killing 176 people. At least 57 Canadians died, most of them of Iranian descent, in one of the biggest single losses of life Canada has suffered in 40 years.

“You may feel unbearably lonely, but you are not alone. Your entire country stands with you, tonight, tomorrow, and in all the years to come,” Mr Trudeau told a crowd of 1700 on Sunday in a basketball gymnasium in Edmonton, Alberta, home to 13 of the victims. Most had direct links to the University of Alberta.

As Mr Trudeau spoke, young children could be heard in the audience, and boxes of tissues were passed among those present. Black-rimmed photos of the dead stood on the stage, where mourners had placed rose petals, candles and plates of dates.

“This tragedy should have never occurred, and I want to assure you that you have my full support during this extraordinarily difficult time. You give us purpose to pursue justice and accountability for you,” said Mr Trudeau.

Family and friends wept and hugged before the vigil started.

Earlier today, Prime Minister Justin Trudeau provided an update on the latest developments in Iran. pic.twitter.com/2L065xxzKp

— CanadianPM (@CanadianPM) January 12, 2020

“Still I’m in shock, still I can’t believe it,” said Vahid Rezania, a friend of Edmonton engineering professor Pedram Mousavi, who was killed.

“I am always thinking, ‘He is going to come. This hasn’t happened’. It is very hard to accept.”

-AAP