"The coach was detached from the rest of the train immediately," said Northern Railways spokesperson.
Smoke was detected soon after the New Delhi-Patna Rajdhani Express had crossed Anand Vihar station.
"We immediately brought the train to a halt between Anand Vihar station and Tilak Bridge station and the coach (the generator car) was detached," the spokesperson said.
The incident comes barely within days of the tragic Kalka Mail accident at Fatehpur which had claimed 69 lives. The fire brigade officials said the fire was of minor nature and five fire tenders were rushed to the spot.