No one was injured, railway sources said.
A handful of passengers in the coach jumped out of the the Ernakulam-Kayamkulam passenger train as it slowed down at the station, the sources said.
According to railway sources, the derailment was caused due to breaking of the coupling that links the coach to the engine.
The incident did not cause any traffic disruption in the Ernakulam-Kayamkulam section.