Kolkata: Sparks from a fan in an non-air conditioned coaches of the Kolkata Metro Thursday triggered panic among commuters and disrupted services for a while.

Commuters on the Kavi Subhas (southern fringes of the city) bound train noticed sparks emanating from one of the cabin fans and raised an alarm. The passengers were subsequently evacuated safely.

"Train services were disrupted for a while before normal services resumed," said a Metro railway spokesperson.

The incident comes barely a month after smoke was detected in a non-AC rake due to overheating in July.

The country's oldest metro transit system has lately been plagued with frequent breakdowns resulting in disruptions of services.

Earlier, in June, hundreds of passengers had a harrowing time after a train in which they were travelling was trapped inside a tunnel following a technical snag.