The Railways clarified there was no fire involved.
A Mumbai-bound train witnessed chaotic scenes in Chennai this evening as passengers ran for their lives seeing smoke on board.
The express train (12164) left Chennai Central at 6:20 pm for Lokmanya Tilak Terminus in Mumbai, and the smoke incident was reported near Basin Bridge around 6:45 pm.
The Railways clarified there was no fire involved.
"It was only an incident of smoke emitting from HOG (Head on Generation) coupler due to ingression of water. The smoke emission occurred from HOG connector between locomotive and power car," the Railways said.
Smoke was seen emanating from the train as panic-stricken passengers rushed out and ran for their lives.
The loco pilot stopped the train immediately and the smoke was arrested by uncoupling the HOG connector, the Railways said.
The train began its journey at 7:22 pm without any other technical issue, it said.
'Head on Generation' locomotive is an energy efficiency system that draws power from the overhead equipment through loco pantograph and caters to the power requirement of the coaches.
A few weeks ago, an air-conditioned coach of Durg-Puri Express caught fire in Odisha, but no casualties were reported. The fire was confined to the brake pads and there was no damage, the East Coast Railway had then said.