An explosion late on Friday night on a Russian train was not caused by a faulty boiler, a representative of the Russian Railways (RZD) company said.
"According to preliminary information, the technical condition of the boiler could not have been the cause of the explosion," the spokesman said.
The blast occurred on a train travelling from the western Russian city of Pskov to Moscow. Witnesses say the carriage was severely damaged in the explosion.
Five people were injured in the blast, including two train attendants, who have been hospitalized with thermal burns.
Officials from the Pskov region Federal Penitentiary Service (UFSIN) were allegedly travelling in the car where the explosion took place. Reports suggest they were on their way to Russia's volatile republic of Chechnya on a business trip. UFSIN has not yet confirmed the claims.
Local police are working to establish the cause of the blast.
MOSCOW, December 4 (RIA Novosti)
