Canadian Prime Minister Justin Trudeau told reporters that the government has reason to believe that the Ukrainian flight that crashed early Wednesday morning near Tehran, killing 176 people, had been shot down by an Iranian missile. “We have intelligence from multiple sources including our allies and our own intelligence: the evidence indicates that the plane was shot down by an Iranian surface-to-air missile,” Trudeau said in a Thursday press conference, according to The Globe and Mail. “This may well have been unintentional.” The prime minister added that the new information “reinforces the need for a thorough investigation into this matter.”

All 176 passengers on board the Ukrainian International Airlines flight were killed when it crashed Wednesday, including at least 63 Canadian citizens. The majority of the people on the flight, 138, were reportedly on their way to Canada at the time. The Daily Beast reported that U.S. officials also believe that flight PS752 was shot down by an Iranian missile while it was en route from Tehran to Kyiv.