From anger to a profound sense of waste, family and friends of those aboard a downed jetliner have been left to process a range of emotions now knowing their loved ones were killed in what Iranian officials have called a horrific military mistake.

"We're in complete shock, we're full of so much emotion," said Nadia Eghbali, whose aunt, uncle and eight-year-old cousin who lived in Toronto died in the crash.

"There's anger, there's so many things, we just don't know why this happened."

Nina Saeidpour, whose friend Kasra Saati died in the crash, said Iran's admission stirred up "mixed emotions."

Saeidpour, from Calgary, said Saati had travelled to Iran over the holidays for a reunion with his wife and two children.

"In some ways we are happy that our government just came forward and said that they did it instead of hiding everything," Saeidpour said. "On the other hand everybody is again in shock about why such a thing should happen."

Iranian President Hassan Rouhani said an Iranian military investigation concluded "missiles fired due to human error caused the horrific crash."

The admission came a day after Iran denied claims being made by Canada, Britain and the United States that Ukraine International Airlines Flight 752 was shot down by Iran, possibly accidentally.

There were 57 Canadian citizens on the plane and 138 of the passengers were bound for Canada, many of them students and professors returning after spending the December break visiting relatives in Iran.

The dead also included many citizens of Iran as well as people from Ukraine, Sweden, the United Kingdom, Afghanistan and Germany.

On Saturday night, hundreds gathered at universities in Tehran to protest the Iranian government's late acknowledgment of the plane being shot down. They demanded officials involved in the missile attack be removed from their positions and tried. Police broke up the demonstrations.

Danny Gonzalez joined an advertising studio in Toronto last year on the same day as Alvand Sadeghi, 29, who died in the crash along with his wife, Negar Borghei, sister, Sahand Sadeghi, and five-year-old niece, Sophie Emami.

"It's just an overall waste," Gonzalez said. "Everything that's related to war and people trying to kill each other for the sake of land or oil, it's always stupid.

"One of the reasons why he picked to move to Canada was it's a place where multicultural people can live in peace."

Mehrdad Taheran, whose friend Mehran Abtahi died in the crash, said he feels "very angry." Abtahi was a post-doctoral research fellow in civil engineering at the University of British Columbia.

It is important that the information found in the black boxes is released, Taheran said.

"It was a deadly mistake that killed many people."

Prime Minister Justin Trudeau said Saturday he was "furious" about the mistake and demanded compensation for the victims' families. Ukraine's President Volodymyr Zelenskiy made similar calls.

Canada may have a case for compensation on behalf of victims, but would almost certainly face hurdles in a country with which it has no formal diplomatic relations, said Lawrence Herman, an international trade lawyer in Toronto.

"In general international law terms, a wrong was committed. And the state that commits that wrong is responsible for compensation," Herman said.

"The question I have is whether the current regime in Iran would be prepared to recognize that obligation."

If Tehran rejects the prospect of damages, Canada could try to seek recourse through the International Court of Justice, though that route can also be contested.

Victims' families could also file civil suits against the government of Iran in a Canadian court, Herman said.

"The Canadian government certainly seems to me to have a right to seek compensation for an act of state that caused damage. That does not foreclose parallel civil actions brought by injured parties."

Reporters Salmaan Farooqui in Toronto, Christopher Reynolds in Montreal and Hina Alam in Vancouver contributed to this report. With files from The Associated Press.

This report by The Canadian Press was first published Jan. 11, 2020.