Moscow police have detained a man suspected of shooting dead four people in the city, an Interior Ministry spokesman said Wednesday.
Bodies with gunshot wounds were discovered Tuesday inside a carriage at a railway cargo terminal in northeast Moscow.
Police found 16 shell casings and five bullets at the scene, investigators said.
The suspect, who police identified only as being born in 1981, was arrested at his friend's apartment in Moscow, an unidentified investigator said.
The investigator said that the suspect has confessed to committing the murders.
Three of the victims were brigadiers and loaders at a construction firm, the Investigative Committee said. The identity of the fourth victim is still being established.