The fire erupted around 2 am at the hotel on Ghalib Street, located in the heart of the eastern Indian city. The area where the building is located is known to be one of the densely populated areas in Kolkata.
The deceased Bangladeshi nationals are believed to have been visiting Kolkata for medical treatment.
The exact cause of the fire is yet to be ascertained. However, preliminary reports suggest that an air-conditioner (AC) explosion may have triggered the blaze.
Firefighters and emergency officials rushed to the spot after the fire was reported. Around 60 people have been rescued from the building so far, several of whom were found unconscious.
A Bangladeshi national who was inside the hotel when the fire broke out told local media that there were no fire extinguishers available in the building.
The incident comes just two days after another deadly hotel fire in West Bengal. On August 17, at least eight people were killed and several others injured after a fire broke out at a hotel in Tarapith in Birbhum district.
The hotel was located near the famous Tarapith Temple.