A technical malfunction on a Moscow metro train forced the partial suspension of services along one of the city’s busiest lines on Tuesday morning.

Moscow’s Transportation Department suspended service on the central stretch of the Sokolnicheskaya Line, commonly known as the Red Line, between the Sokolniki and Park Kultury stations.

Officials urged stranded commuters to seek alternative routes via buses, trams or other metro branches.

Yulia Temnikova, deputy chief of the Moscow Metro, denied media reports that a train had derailed. She said the incident on Tuesday was a “technical malfunction” related to the wheels of a train car.

Videos published by Russian media showed damage to a connection point between two train cars. Other footage captured smoke filling platforms at several stations along the line.

While transportation officials said that all passengers were safely evacuated without injury, some local media outlets reported that an elderly man was hospitalized with broken bones following a chaotic evacuation from the tunnel.

By noon local time, officials said service had been partially restored on the Red Line’s northeastern section, though repair crews continued to work on the central stations to bring the full line back into operation.