Irked over the delay of an EMU train between Chengalpattu and Beach, over 500 passengers blocked it in a flash protest at the Urapakkam station.
The Express and EMU train services were affected for over 20 minutes during the rush hour on Monday morning.
The protesters said that the train which had been stopping at the select stations, now stopped at all of them.
The delay caused by this made them late for work.
They dispersed after Railway officials assured them the problem would be solved.