Video taken by Mumbai resident Mihir Bijur shows flames and black smoke rising above a slum in Mumbai on Monday (December 7).
The fire started in a warehouse and swept through the slum in India's financial capital triggering a set of gas cylinder explosions, fire brigade and police officials said.
Bijur's video shows the burned out remnants of the slum with the sound of emergency services sirens in the background.
Broadcaster NDTV reported two people died in the fire in a northern suburb and a Reuters photographer said he saw one body in the wreckage. A city hospital employee said at least four casualties had been brought in by rescue workers, but fire fighters said others had been taken to private hospitals.
Fire fighters said cramped conditions in the slum, which houses a number of shacks used for storage, made it difficult for the fire brigade to reach the blaze. They feared residents might have become trapped in the wreckage.
More than 100 huts were destroyed, said the Reuters photographer at the scene, adding that residents were picking through the smoking remains of their homes as fire fighters doused the last of the blaze.