Canada has intelligence from multiple sources that the Ukrainian airliner was shot down by an Iranian surface-to-air missile, said Canadian Prime Minister Justin Trudeau, adding that the action by Tehran may be 'unintentional'.
"We have intelligence from multiple sources including our alliance and our own intelligence and the evidence indicate that the plane was shot down by an Iranian surface to air missile. This may have been unintentional," Trudeau said during a conference.
The Boeing 737 jet with 176 people on board including 63 Canadians crashed minutes after taking off from Tehran on Wednesday morning.
Eighty-two Iranians, 63 Canadians, and 11 Ukrainians died in the crash, which took place between the cities of Parand and Shahriar. There were also 10 Swedes, four Afghans, three Germans and three British nationals among the victims.
Earlier in the day, CNN reported that the United States believed that Iran mistakenly shot down a Ukrainian airliner. US President Donald Trump has indicated the plane crash was not due to mechanical issues, adding that "somebody could have made a mistake on the other side."
The crash took place on the day Iran had launch missiles US targets in Baghdad in retaliation to the killing of Iranian military leader General Qassem Soleimani.
Meanwhile, Ukraine has opened an investigation to find out the cause of the crash. The country's officials said they are looking into multiple causes for the crash including the missile strike or terrorism.
Sweden has also joined the crash investigation on Thursday. Sweden Minister of Foreign Affairs Anne Linde told CNN that nothing was ruled out concerning the causes of the plane crash.
The United Kingdom is looking into "very concerning" reports about the Iran plane crash, a Downing Street spokesperson said.
Meanwhile, European security officials said they believe that reports suggesting that the Ukrainian airliner was shot down by an Iranian surface to air missile in error are credible.
Ali Abedzadeh, the chief of Iran's Civil Aviation Organisation, wrote in a preliminary report on the crash that both of the plane's black boxes have been damaged, with physical damage visible.
"Both devices have been damaged by fire and the accident. There are the memory parts in both devices, however, physical damage is visible on them," the report wrote.