Authorities in Moscow say last week's deadly train collision near the capital was caused by a violation of track maintenance rules.
Russian Investigative Committee spokesman Vladimir Markin said on May 22 that the drivers of the two trains that collided on May 20 near the town of Naro-Fominsk had not been informed about repair works along the track.
Six people, all Moldovan citizens, were killed and 24 were hospitalized as a result of the collision.
Markin said that Aleksandr Sokolov, 41, the supervisor of the Moscow-Kyiv railway line, has been detained as part of an ongoing criminal investigation.
The director of the line stretch, whose name was not made public, is also under investigation.
Based on reporting by ITAR-TASS and Interfax