Russian authorities said Tuesday a freight train derailed overnight due to suspected sabotage near Volgograd in the country's southwest, with a wagon and a fuel storage tank catching fire.
"Due to the intervention of unauthorised persons, wagons from a freight train derailed in the Kotluban station," the local branch of the rail operator said.
There were no casualties in the incident which happened at 2215 GMT on Monday, it said, adding that train services resumed a few hours later.
The emergency situations ministry said a fuel storage tank and a wagon caught fire but the blaze was quickly extinguished.
The incident is the latest in a spate of suspicious fires and derailments on Russia's rail network.
Kotluban is about 300 kilometres (about 190 miles) from the Ukrainian border and Volvograd has been targeted by Ukrainian drones.
Kyiv has not claimed responsibility for the incident.
Russia has blamed similar incidents on Ukraine and its supporters.
In December, Russia arrested a Belarusian man for allegedly placing explosives on two trains on a key part of a Siberian railway near the Chinese border on Ukraine's orders.
In January this year, Russian investigators said two teenagers who set fire to a railside equipment box in Moscow had been charged with carrying out sabotage for Ukraine.