A Boeing 737 has crashed on landing in the Russian city of Kazan, killing all 50 people on board.
The flight from Moscow was making a second attempt to land but exploded when it hit the runway killing all 44 passengers and six crew on board.
The flight was operated by the regional Tatarstan airline, a ministry spokeswoman said.
Flight U363 took off from Moscow's Domodedovo airport at 6.25pm (2.25pm Irish time) and crashed just over an hour later, emergency officials said.
The plane was 23 years old.
According to eyewitness reports, the Boeing lost altitude quickly and its fuel tank exploded on impact.
There were high winds and cloudy skies over the airport in central Russia.
Temperatures were above zero.
Kazan, which is 800km east of Moscow, is capital of the largely-Muslim, oil-rich region of Tatarstan.
A new runway was built at the airport ahead of the World Student Games, held in the city earlier this year.
A spokesman for state aviation oversight agency Rosaviatsia said authorities would search for the flight recorders.
Russia and the former Soviet republics combined had one of the world's worst air-traffic safety records in 2011.
Its total accident rate almost three times the world average, according to the International Air Transport Association.
The Boeing 737 is the world's most popular passenger jet in commercial use today.
There have been 170 crashes involving this model of aircraft since it came into use.