The deadly crash of an Ukrainian airliner in Iran was caused by an anti-aircraft missile, said a Pentagon official, a senior U.S. intelligence official and an Iraqi intelligence official according to a report in Newsweek Thursday.
The Ukrainian International Airlines Boeing 737-800 travelling to Kiev, crashed on Wednesday, shortly after taking off from Tehran's Imam Khomeini airport, killing all 176 people on board.
According to the report, the plane is said to have been struck by a Russia-built Tor-M1 surface-to-air missile system, which NATO calls Gauntlet.
The incident occurred just hours after Iran fired at least 16 ballistic missiles on an Iraqi military base housing U.S. troops in response to the killing of Gen. Qassem Soleimani.
The report says that U.S. officials believe that because the Iranian defense systems were on high alert following the retaliatory strike, they misidentified the Ukrainian plane as an American threat and mistakenly launched the anti-aircraft missile.
One U.S. official said U.S. satellites had detected the launch of two missiles shortly before the plane crashed, followed by evidence of an explosion.
The Pentagon declined to comment.
President Donald Trump also suggested that he believes Iran was responsible. Although he wouldn't directly lay the blame on Iran, he dismissed the Islamic Republic's initial claim that it was a mechanical issue. "Some people say it was mechanical," Trump said. "I personally don't think that's even a question."
"Somebody could have made a mistake on the other side," Trump added, noting the plane was flying in a "pretty rough neighborhood."
The Iranian report cited witnesses on the ground and in a passing aircraft flying at a high altitude as saying the plane was on fire while in the air.
It said the three-year-old airliner, which had its last scheduled maintenance on Monday, encountered a technical problem shortly after take-off and started to head toward a nearby airport before it crashed.
The report said there was no radio communication from the pilot and the aircraft disappeared from radar at 8,000 feet (2,440 m).
The Iranian report referred to the crash as an accident.
Ukraine, meanwhile, said it considered a missile strike as one of several possible theories for the crash, despite Iran's denials.