Justin Trudeau has said evidence suggests a missile brought down a Ukrainian passenger plane that crashed near Tehran earlier this week.
The Canadian prime minister said he had received intelligence from multiple sources indicating that the plane was shot down by an Iranian surface-to-air missile.
He added that it was possible that this was unintentional.
“This reinforces the need for a thorough investigation,” Trudeau said.
“Canadians have questions and they deserve answers.”
However, the prime minister cautioned it was too early to apportion blame or draw any conclusions, and refused to go into detail about the evidence.
All 176 people on board a Ukraine International Airlines Boeing 737-800 were killed when it came down shortly after take-off from Tehran on Wednesday.
Victims onboard flight PS752 included 82 Iranians, 63 Canadians and 11 Ukrainians as well as nationals from Sweden, the UK, Afghanistan and Germany.
The crash came just hours after Iran carried out missile strikes on two airbases housing US forces in Iraq.
United States president, Donald Trump, said on Thursday that he had “suspicions” about what happened to the plane, while British prime minister, Boris Johnson, has called for an investigation.