Police sourcees said the fire, which broke out in the generator room around 11 pm, could be put off promptly as the bank employees informed the fire brigade and also pressed into service the fire extinguisher machine.
Two fire tenders put off the flames in less than a hour's time.
There was no report of any injury or casualty.
Due to the fire the customers came out of the adjacent bank building as thick smoke clouded the area but the situation came to normal soon.