Forty-one people are believed to have died after a Russian passenger plane made an emergency landing at Moscow's busiest airport and caught fire, investigators said.
"There were 78 people including crew members on board the plane," the Investigative Committee said in a statement.
"According to the updated info which the investigation has as of now, 37 people survived."
Two children are among those confirmed dead following the inferno on the Sukhoi Superjet at Sheremetyevo airport on Sunday, the Russian Investigative Committee said.
Terrified passengers were seen fleeing the Russian national carrier Aeroflot plane as flames flared from the rear of the aircraft with 78 on board.
Shocking footage from on board the Russian-built plane as it landed captured horrific flames engulfing the windows and the screams of passengers as they were gripped by panic.
JUST IN: Video shows horror inside burning passenger plane which made an emergency landing at Sheremetyevo Airport in Moscow. The fire killed at least 13 people, including 2 children: pic.twitter.com/YE4h4B2EeC— Live Report (@tweetlivereport) May 5, 2019
Yet an airport official said that "many passengers delayed emergency evacuation - because against all instructions - they were picking up hand luggage from overhead compartments".
The aircraft made two attempts to crash land soon after take-off from Russia's capital to the Arctic city of Murmansk.
Initial indications suggest an electrical fault might have caused the fire while the plane was in the air.
One passenger said: "I was sitting in front of the engine, and saw how everything melted.
"Somehow I managed to reach the exit, inhaling carbon monoxide. The flight attendants said: 'Come on, quickly, crawl, a little bit left until the exit'. As a result, I managed to jump off the plane."
Aeroflot said the passenger plane was forced to turn back after takeoff because of technical problems.
In a brief statement it said the engines of the Sukhoi SSJ100 were burning after the aircraft landed, but the sequence of events before and after the fire started was not clear.
Some Russian news reports cited sources as saying the plane headed back to the airport after a fire was detected in flight. Others said the plane made a hard landing that could have caused the engines to catch fire.
A spokeswoman for the crash investigation team, Svetlana Petrenko, said: "For the moment, we confirm the death of 13 people, two of them children."
Another 11 people were injured, said Dmitry Matveyev, the Moscow region's health minister. Three of them had been hospitalised but they were not in a serious condition, he added.
A flight attendant who attempted to rescue some of the 73 passengers from the blaze was said to be among the dead. He was named locally as Maxim Moiseev. There were five crew members on board.
Interfax agency reported that the plane, a Russian-made Superjet-100, had just taken off from Sheremetyevo airport on a domestic route when the crew issued a distress signal.
"It attempted an emergency landing but did not succeed the first time, and on the second time the landing gear hit (the ground), then the nose did, and it caught fire," a source said.
It reported that the tail was completely burned and said a rescue team was trying to find survivors in that part of the plane.
Ambulances were sent to the scene of the landing and the passengers were evacuated, with the airport now closed for arrivals and departures.
However, there were local reports of emergency services being refused access to the scene with paramedics held at checkpoints for up to seven minutes.
The airline said the number of victims was "being specified" and that emergency medical care was being provided to the injured.
Footage showed a column of smoke towering over the plane. Other images showed the aircraft on fire as it attempted to land, then distraught passengers leaving by a forward door.
Video captured passengers leaping from the plane onto an inflatable slide from the front of the aircraft and staggering across tarmac and grass of the airport.
The stricken plane was clearly visible from the main terminals at the airport in the north of Moscow and a British Airways plane could be seen on the tarmac alongside it.
A passenger called mikkentosh posted on social media: 'Guys I am all right, I am alive and in one piece.
"I managed to jump out. This was the 17.50 Moscow to Murmansk flight. Definitely not everyone managed to escape, huge condolences to families and friends."
The Sukhoi Superjet-100 was the first civilian aircraft developed in Russia's post-Soviet era and at the time of its launch, in 2011, was a source of national pride.
But it struggled to convince buyers from airlines outside Russia, and several foreign airlines that did buy it have since preferred to cut back its use or phase it out completely, citing its reliability.
The Russian government offered subsidies to encourage Russian airlines to buy the Superjet and Russian airline Aeroflot became its main operator. In September 2018, it announced a record order of 100 Superjet-100s.
Criminal investigators are examining the cause of the crash amid reports that an electrical fault had caused the inferno after take-off.