The accident happened in the Bryansk region, which borders Ukraine. The independent newspaper Novaya Gazeta Europe posted a video on Twitter showing several derailed tank cars and a fire with dark smoke rising.
"An unidentified explosive device went off on 136 km of the Bryansk-Unecha railway in the Unechsky district, causing a freight train locomotive to derail. There were no casualties. Emergency services are currently on the scene. Traffic on this section has been suspended," wrote the governor of the region, Alexander Bogomaz, on the Telegram social network.
According to Reuters, Russian Railways, the national railway operator, said the incident occurred at 10:17 Moscow time (0717 GMT). It said the locomotive and seven goods wagons were derailed and the locomotive caught fire.
It is not yet known who was responsible for the attack.