Fifty people died Sunday in Russia when a Boeing 737-500 passenger jet crashed at the airport in Kazan, the capital of the republic of Tatarstan.

All 44 passengers and six crewmembers died upon impact, and the plane broke into several parts and exploded, according to preliminary information released by Tatarstan Airlines.

"Judging from the remains of the aircraft, it would have been+++ difficult for anyone to be able to survive," a transportation services spokesman told the official RIA-Novosti news agency.

The Boeing 737, one of the world's most widely used civilian aircraft, crashed on the Kazan airport runway about 7:26 p.m. as it was trying to regain speed and altitude after aborting an initial landing attempt.

The plane lost altitude for unknown reasons as it was attempting to circle the airport to try landing again, and it plunged nose-first into the ground, officials said.

Flight 363 had taken off an hour earlier from Moscow's Domodedovo international airport and burst into flames upon impact, although firefighters were able to extinguish the blaze. EFE