<p>A Ukraine airliner that crashed in Iran, killing all 176 people aboard, was most likely brought down accidentally by Iranian anti-aircraft missiles, U.S. officials said on Thursday.</p>.<p>According to satellite data, one U.S. official said, the Ukrainian International Airlines Boeing 737-800 bound for Kiev was airborne for two minutes after departing Tehran when the heat signatures of two surface-to-air missiles were detected.</p>.<p>That was quickly followed by an explosion in the vicinity of the plane, the official said. Heat signature data then showed the plane on fire as it went down.</p>.<p>Iran's head of civil aviation was quoted by ISNA News Agency as saying that it was "impossible that a missile hit the Ukrainian plane."</p>.<p>Two U.S. officials said Washington believed the downing of the plane, which occurred at a time of rising tensions between Iran and the United States, was accidental.</p>.<p>An Iranian report on Thursday 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.</p>.<p>U.S. President Donald Trump said on Thursday the deadly crash could have been a mistake and he did not believe it was a mechanical issue.</p>.<p>Boeing and the Federal Aviation Administration declined to comment on Thursday, as did the Pentagon.</p>.<p>Boeing is still reeling from two deadly crashes of 737 MAX planes in five months that led to the plane's grounding in March 2019. The 737-800 that crashed was built in 2016 and is the prior generation of the 737 before the MAX. Boeing has built about 5,000 of those planes, which has a good safety record.</p>
<p>A Ukraine airliner that crashed in Iran, killing all 176 people aboard, was most likely brought down accidentally by Iranian anti-aircraft missiles, U.S. officials said on Thursday.</p>.<p>According to satellite data, one U.S. official said, the Ukrainian International Airlines Boeing 737-800 bound for Kiev was airborne for two minutes after departing Tehran when the heat signatures of two surface-to-air missiles were detected.</p>.<p>That was quickly followed by an explosion in the vicinity of the plane, the official said. Heat signature data then showed the plane on fire as it went down.</p>.<p>Iran's head of civil aviation was quoted by ISNA News Agency as saying that it was "impossible that a missile hit the Ukrainian plane."</p>.<p>Two U.S. officials said Washington believed the downing of the plane, which occurred at a time of rising tensions between Iran and the United States, was accidental.</p>.<p>An Iranian report on Thursday 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.</p>.<p>U.S. President Donald Trump said on Thursday the deadly crash could have been a mistake and he did not believe it was a mechanical issue.</p>.<p>Boeing and the Federal Aviation Administration declined to comment on Thursday, as did the Pentagon.</p>.<p>Boeing is still reeling from two deadly crashes of 737 MAX planes in five months that led to the plane's grounding in March 2019. The 737-800 that crashed was built in 2016 and is the prior generation of the 737 before the MAX. Boeing has built about 5,000 of those planes, which has a good safety record.</p>