Nobody was injured in the mishap, it said.
Four rear wheels of the Tirumalpur-Chennai Beach electric multiple unit train derailed at Chengalpattu station yard "obstructing track," a release said.
The derailment happened when the train was leaving Chengalpattu station on its way here.
"Immediately, Breakdown special and medical relief van was rushed to spot. All passengers are safe," it said.
No passenger suffered any injuries, it said, adding the 'obstruction' was cleared within an hour of the incident "for free movement of up and down trains.