The Ukrainian airliner, which crashed outside Tehran with the loss of all 176 people on board, turned back after suffering a problem, according to the Iranian authorities.
Both Canada and the United States have called for a full investigation to determine the cause of Wednesday’s crash, which came shortly after Tehran launched missiles at US troops in Iraq in response to the killing of a top Iranian general in a US drone strike in Baghdad.
There was no immediate indication that foul play may have caused the Ukraine International Airlines (UIA) plane to go down soon after take-off, and Ukrainian President Volodymyr Zelensky warned against speculating on the crash causes.
“The plane, which was initially headed west to leave the airport zone, turned right following a problem and was headed back to the airport at the moment of the crash,” the Iranian Civil Aviation Organisation said on its website late Wednesday.
“The plane disappeared from radar screens the moment it reached 8,000 feet (2,400 metres). The pilot sent no radio message about the unusual circumstances.
“According to eyewitnesses, a fire was seen onboard the plane which grew in intensity,” the organisation added, reporting the first findings of its investigation into the crash.
The organisation said it had questioned witnesses both on the ground and onboard a second aircraft which was flying above the Ukrainian Boeing 737 as the disaster unfolded.