The Canadian government has intelligence from "multiple" sources that shows an Iranian anti-aircraft missile likely brought down a Ukrainian passenger plane that crashed near Tehran on Wednesday morning , Prime Minister Justin Trudeau told a news conference on Thursday.

"The intelligence evidence suggests very clearly a possible and probable cause for the crash," he said, adding that a strike "may have been unintentional."

All 176 people on board were killed when the Kyiv-bound Ukrainian International Airlines flight crashed outside the Iranian capital minutes after taking off in the early hours of Wednesday. At least 63 Canadians, 82 Iranians, 11 Ukrainians and 4 Britons were among the dead.

US officials told various local media and news agencies on Thursday that they also believed an Iranian missile brought down the plane accidentally.

Speaking to reporters at the White House, US President Donald Trump said he had suspicions that "somebody could have made a mistake," without going into detail.

"Some people say it was mechanical. I personally don't think that's even a question," Trump said, adding that "something very terrible happened."

Trudeau and Trump's comments were echoed by British Prime Minister Boris Johnson, who said that there is "a body of information" that the plane was brought down by an Iranian missile.

Read more: Why the US and Iran are not at war

Investigation underway

Iran has denied it is responsible for the plane crash, which it says was likely caused by a technical malfunction. The assessment from US officials came as Tehran released an initial report into the incident that said the pilots did not put out a call for help, but had been trying to return to the airport when the aircraft went down. 

The report also said that both of the plane's black boxes — which record flight data — had been recovered for analysis, although they had sustained some damage.

Iranian government spokesman Ali Rabiei invited US plane manufacturer Boeing to take part in the investigation process. He also denied that a missile caused the crash, calling such accusations "psychological warfare against Iran."

Iran has also invited the US National Transportation Safety Board (NTSB) — the US accident-investigating body — to join the efforts. The NTSB confirmed its participation late Thursday. 

Illogical 'rumors'

One US official cited by Reuters said US satellites had detected the launch of two surface-to-air missiles shortly after the Boeing 737-800 left Tehran. That was followed by an explosion in the area the plane had been traveling in, the official said, adding that heat signature data showed the aircraft on fire as it fell to the ground.

However, the head of Iran's Civil Aviation Organization, Ali Abedzadeh, said it was "impossible that a missile hit the Ukrainian plane."

"Such rumors make no sense," he was quoted by ISNA news agency as saying. 

A video posted by investigative group Bellingcat, which specializes in analyzing publicly available information, purported to show a mid-air explosion and a possible location from which a missile may have been fired. 

The crash happened only hours after Iran launched a ballistic missile attack on Iraqi military bases where US troops were being housed.

Tensions between Washington and Tehran soared following the US killing of Iranian General Qassem Soleimani last week.

Read more: How does a black box work?

Ukraine said it was looking into a number of possible scenarios to explain the crash, including a missile strike, an in-flight collision and terrorism. It sent a team of experts to Iran on Thursday to help investigate on the ground.

"The circumstances of this catastrophe are still unclear," Sergiy Kyslytsya, Ukraine's deputy foreign minister said at a UN meeting in New York. "It's now up to experts to investigate and to find answers to the question of what caused the crash. To do so, our experts must receive unconditional support for their investigation."

Canada has called for its own team to also be involved in the probe.

kp, nm, jsi/ng (Reuters, AFP, AP)

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