Forty-one people died when a burning Russian passenger made an emergency landing at a Moscow airport, a Russian news agency has reported.
Footage showed the Russian Aeroflot Sukhoi Superjet-100 making an emergency landing at Moscow's Sheremetyevo airport with much of the rear part of the plane engulfed in flames.
Videos on social media showed passengers using emergency exit slides to escape and run away from the burning Aeroflot aircraft.
The plane carrying 78 people took off from the Moscow airport at 5.50pm (local time) bound for the city of Murmansk.
Medical workers initially told the TASS news agency at least 13 people had been killed, but investigators now say 41 people are dead.
There were 73 passengers and five crew members on board, Russia's aviation watchdog said.
It remains unclear what caused the large blaze and emergency landing.
The Interfax news agency reports the crew issued a distress signal shortly after departure from Sheremetyevo airport.
No official cause has yet been given for the incident although some surviving passengers spoke of a lightning strike.
"We took off and then lightning struck the plane," the Komsomolskaya Pravda daily cited one surviving passenger, Pyotr Egorov, as saying.
"The plane turned back and there was a hard landing. We were so scared we almost lost consciousness. The plane jumped down the landing strip like a grasshopper and then caught fire on the ground."
Russia's Investigative Committee said it had opened an investigation and was looking into whether the pilots had breached air safety rules.
The Flightradar24 tracking service showed that the plane had circled twice over Moscow before making an emergency landing after about 45 minutes.
The plane's undercarriage gave way on impact and its engines caught fire.
Interfax cited a source as saying the plane had only succeeded making an emergency landing on the second attempt and that some of the aircraft's systems had then failed.
The emergency landing was so hard that debris had found its way into the engines, sparking a fire that swiftly engulfed the rear of the fuselage, the same source said.
Russian investigators said they were looking into various versions.
Russian news agencies reported that the plane had been produced in 2017 and had been serviced as recently as April of this year.
Aeroflot has long shaken off its troubled post-Soviet safety record and now has one of the world's most modern fleets on international routes where it relies on Boeing and Airbus aircraft.
Interfax said a rescue team was combing through the charred wreckage of the rear of the plane looking for survivors.
Kristian Kostov, a former Bulgarian Eurovision contestant, posted on social media about witnessing the incident.
He said people at the airport were left "shaking" after seeing the aircraft engulfed by fire and said other flights are now unable to take-off.
- Reuters / BBC