The sound of an explosion at the Suthisarn underground train station about 8am sent waiting waiting commuters rushing from the platform in fear, Post Today Online reported.
The operator, Mass Rapid Transit (MRT), then announced there was a power disruption at the station.
It said there would be a brief delay in the service and apologised for the inconvenience.
The service returned to normal about five minutes later.
About 8.40am, the MRT governor confirmed the explosion was the sound of a power short-circuit on a train, which also emitted some of smoke.
There were no reports of injuries.
