Ukrainian investigators have indicated that a Boeing 737-800 which crashed shortly after departing Tehran had suffered an in-flight fire.

The Ukrainian investigation authority NBAAI says the preliminary information has been obtained from “media sources”.

It has not identified these sources, although an undated segment of video footage – which has not been officially authenticated – has been circulating on social media purporting to show the aircraft apparently ablaze and shedding parts while flying in darkness.

Iranian investigators have not disclosed any findings from the inquiry into the loss of the Ukraine International Airlines aircraft.

NBAAI says the aircraft (UR-PSR) had been bound for Kiev, adding that the accident took place at around 06:15 local time, about 2min after take-off.

None of those on board survived, it says. NBAAI adds that it has established a commission to participate in the investigation.