Commuters on the Moscow metro had to wait inside halted trains Monday morning while police searched for a man who was riding on the outside of a train.
Police detained the rider, who had been hiding in the gap between two wagons, at the Noviye Cheryomushki station, police said, Interfax reported.
Subway technicians had to cut off the power supply to the train for about 10 minutes to allow police officers to apprehend the man, a police spokesman said.
The rider may be taken to a hospital for a medical evaluation, the spokesman said.
Witnesses earlier spotted the man riding on the outside of a train at the Leninsky Prospekt station on the Orange Line, news reports said.
Subway operators held the outbound train at several stations between Leninsky Prospekt and Noviye Cheryomushki, as police patrols tried to find the man.