Jan. 9 (UPI) -- Canadian Prime Minister Justin Trudeau said Thursday that the country has intelligence indicating a Ukrainian airliner that crashed in Tehran this week was shot down by an Iranian missile.
He made the statement during a televised news conference about the crash, in which 63 people carrying Canadian passports died. None of the 176 people on board the plane survived.
"We have intelligence from multiple sources, including our allies and our own intelligence," Trudeau said. "The evidence indicates that the plane was shot down by an Iranian surface-to-air missile. This may well have been unintentional."
The prime minister didn't offer any details about the evidence, but said he and the families of the victims want answers about what happened.
"That means closure, transparency, accountability and justice," he said. "This government will not rest until we get that."
U.S. intelligence officials also disputed Iranian investigators' claim, that a technical failure is most likely to blame. CNN, CBS News, NBC News and Newsweek all reported Thursday that intelligence officials believe the airliner was accidentally downed by an Iranian missile.
After analyzing satellite and radar data, U.S. officials said a "working theory" indicates Ukraine Airlines Flight PS752 was mistakenly attacked by Iranian forces. The crash occurred shortly after Iran launched two missile attacks at a pair of U.S. bases in Iraq.
U.S. satellites detected two surface-to-air missile launches shortly before the plane went down, the CBS News report said.
The New York Times also obtained footage purporting to show an Iranian missile hitting the plane near the airport. The newspaper said it verified the authenticity of the video.
In the video, a missile appears to strike the aircraft, causing a small explosion. The plane continued to fly and attempted to turn back toward the airport before experiencing a larger explosion and crashing.
Speaking at a White House event Thursday, U.S. President Donald Trump told reporters he isn't so sure the crash resulted from mechanical trouble.
"I have my suspicions," he said. "Somebody could have made a mistake on the other side. ... Something very terrible happened."
Trump noted the plane was flying in a "rough neighborhood."
Iranian officials immediately rejected U.S. suspicions. Tehran's chief civil aviation chief called the U.S. suspicions "illogical rumors."
What is certain is the jetliner crashed a few minutes after departing Khomeini International Airport, about 35 miles southwest of Tehran.
The Iranian Civil Aviation Organization said in a preliminary report earlier Thursday the plane was attempting a return to the airport when it crashed, and that witnesses saw the 737 on fire. Immediately following the crash on Wednesday, Iranian officials said a technical failure on board was likely responsible.
The agency said the plane climbed to an altitude of 8,000 feet before disappearing from radar. However, it noted, neither of the pilots on board reported trouble to ground controllers.
Investigators have recovered the "black boxes" -- the plane's flight data and cockpit voice recorders -- and said both were damaged, but usable. Iran has refused to turn the recorders over to U.S.-based Boeing.
The Ukrainian airline and officials in Kiev have dismissed the possibility the crash was the result of pilot error.
"Given the crew's experience, error probability is minimal. We do not even consider such a chance," UIA Vice President of Operations Ihor Sosnovsky said in a statement, adding that the pilots' experience on the aircraft ranged from 7,600 to 12,000 hours.
"We will surely find out the truth," Ukrainian President Volodymyr Zelensky said. "For this purpose, a thorough and independent investigation will be conducted in accordance with international law."
Forty-five specialists from Ukraine are working with Iranian investigators at the site.
"We expect that they will all be included in the work of the commission, in particular, the decoding of the 'black box' records," Zelensky said.
Ukrainian officials are also looking into the possibility the plane was downed by a missile. Security Council Secretary Oleksiy Danylov said investigators are eyeing several possible causes -- including an anti-aircraft missile, like the Russian-made Tor -- after reports of potential missile fragments found at the crash site.
Other scenarios being discussed, Danylov said, included a collision with a drone, the technical failure of an engine or terrorist sabotage.
Boeing, which for nearly a year has been dealing with the crashes of two 737 Max 8s that grounded the model worldwide, said in a statement it's "ready to assist in any way needed."
Officials said 82 Iranians, 63 Canadians, 11 Ukrainians, 10 Swedes, four Afghans, three Germans and three Britons all died in Wednesday's crash. Ukraine declared Thursday a day of mourning. Swedish and British officials said they are actively looking into the possibility of a missile shoot down.
The crash comes amid escalating tensions between Iran and the United States. Last week, Trump ordered the airstrike that killed Iranian Gen. Qassem Soleimani, for which Tehran retaliated by firing at least a dozen missiles at two U.S. military bases in Iraq.