At least seven people have been killed when a bridge collapsed onto a railway in a Russian region bordering Ukraine, a governor said, which Moscow Railways blamed on "illegal interference".

"There are seven dead as a result of the collapse of a bridge onto railway tracks. Thirty victims, including two children, were taken to medical facilities of the Bryansk region," Aleksandr Bogomaz, the regional governor, wrote on Telegram on Saturday.

Moscow Railways said a train derailed "between Klimov and Moscow due to the collapse of a road bridge span, as a result of illegal interference in the operation of transport".

Bogomaz said emergency services and government officials are working at the scene. "Everything necessary is being done to provide assistance to the victims."

Investigators are also inspecting the scene, according to the Western Interregional Investigative Department for Transport of the Investigative Committee of the Russian Federation.