OTTAWA -- Canadian Prime Minister Justin Trudeau said on Thursday that his government has intelligence indicating that an Iranian surface-to-air missile shot down the Ukraine International Airlines plane, which crashed Tuesday near Tehran with all 176 people on board confirmed dead.

"We have intelligence from multiple sources including our allies and our own intelligence," said Trudeau at a press conference held in Ottawa on Thursday afternoon, adding that this incident "may well have been unintentional."

There were 63 Canadian citizens among the passengers aboard the ill-fated Ukrainian flight.

Trudeau's comments came on the heels of U.S. media reports on Thursday that U.S. officials "increasingly believe" the passenger plane was mistakenly shot down by Iran.

The Iranian authorities have repeatedly denied allegations or speculation that the crash of the Ukrainian flight was caused by an Iranian missile attack.

"Technical failure has been the cause of the incident," Iran's Minister of Road and Urban Development Mohammad Eslami told the press on Thursday. He said the Boeing 737 plane caught fire due to a technical failure, which caused its communication and control systems to stop working and resulted in its crash.

Iranian technicians and experts from Boeing will examine data from the black boxes recovered from the crash site to determine the cause of the crash, said the minister.