A passenger and a freight train have collided in the south-west of Moscow, killing at least five people and leaving up to 45 wounded.
A preliminary report from the Russian Interior Ministry has confirmed that four people were killed and 15 were seriously injured.
The Moscow Transport Police Department press service reported: "A freight and a commuter train collided on the Bekasovo-Nara railroad near the regional centre of Naro-Fominsk."
The site of collision is located on the Kiev-bound railway some 55km (34 miles) from Moscow city centre. The passenger train was travelling from Moscow to Chisinau, Moldova, when the accident occurred.
The reason for the collision was not immediately clear, but according to reports, the derailed cars of the freight train hit the passenger train, which was passing by at the same time.
According to police officials, 16 cars of the freight train and three cars of the passenger train came off the rails.
Emergency services team, including rescuers and paramedics, have already rushed to the scene.
Naro-Fominsk Region head Vadim Andronov was quoted as saying: "It is possible that the number of dead and injured passengers will grow as one overturned passenger carriage has been blocked by a container from the freighter train, which now remains on top of it. Rescuers are entering the second damaged passenger carriage right now."
All services on the damaged railway line have been temporarily suspended. Approximately 45 repair personnel and 16 units of equipment have been drafted in by Russian Railways to carry out repair work and to put the carriages back on the rails.