Kolkata/UNI: A fire broke out at a chemical godown of a multi-storey building in the congested residential area of Bowbazar in the central part of the city on Friday, even as the firefighting men engaged to douse the flames, official sources said.

There had been no report of any casualties when the report of the blaze came in.

The incident happened in the basement of the building around 0700 hours at BB Ganguly Street, which also housed many residents and commercial offices on the upper floors.

The firefighters have already evacuated most of the people safely, but the search was on amid black smoke if anyone, especially elderly people, left there, police added.

The rescue operation was hampered due to the blasting of the chemical barrels and narrow pathways of the century old building, which has only one entry and exit route.

At least five firefighting vehicles were pressed into the services to combat the fire.

Sources said the firefighting men were trying to source the blaze because the godown in the basement, which has very poor entry and is dark.