The Tatarstan airlines flight from Moscow was trying to abort its landing in order to make a second approach, but it exploded on hitting the runway, killing all 44 passengers and six crew on board, emergency officials said.
The only picture shown from the scene on Russian television reports was a blurred still shot of the plane's fuselage with firefighters in the foreground, apparently after they had extinguished a fire at the scene.
Flight U363 took off from Moscow's Domodedovo airport at 6:25 pm (1425 GMT) 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.
Boeing officials at the Dubai Airshow declined to comment on the crash.
Kazan, which is 800 km (500 miles) 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.
Russia will host the Winter Olympics in the southern city of Sochi early next year.
Russia spans nine time zones, from the Baltic Sea to the Pacific across large areas of largely uninhabited land, making efficient air travel and train links especially important to the country's economy. In Soviet times Aeroflot had a virtual monopoly of the airline industry, but after the collapse of the Soviet Union, a multitude of small private companies emerged.
A spokesman for state aviation oversight agency Rosaviatsia said authorities would search for the flight recorders.
"The plane touched the ground and burst into flame," Sergei Izvolsky said. "The cause of the crash as of now is unknown."
Russia and the former Soviet republics combined had one of the world's worst air-traffic safety records in 2011, with a total accident rate almost three times the world average, according to the International Air Transport Association.
IATA said last year that global airline safety had improved but that accident rates had risen in Russia and the ex-Soviet Commonwealth of Independent States.
In April 2012, at least 31 people were killed when a Russian passenger plane crashed shortly after take-off in Siberia.
In September 2011, a Yak-42 passenger jet carrying members of a major league ice hockey team came down shortly after take-off and burst into flames near the Russian city of Yaroslavl, killing 44 people.
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.
In the Russian city of Perm in 2008, a Boeing 737 exploded just a few kilometres above the ground minutes before landing, killing 88 people.