Seven people died and 40 injured in a fire that broke out at an industrial estate, housing chemical units in central Mumbai on Monday.

The fire started in the third floor of the Retiwala Industrial Estate building at around 3:30 pm and quickly spread trapping those above, they said.

At least 12 fire engines and ten tankers were rushed to the spot to evacuate people working in the building, fire officials said, adding the blaze was put out after nearly three hours.

The cause of the fire has not yet been ascertained and investigations would be carried out in due course, they said.

The police will also be carrying out investigations into the nature of the chemicals that were being stored in the industrial units housed in the building, Additional Commissioner of Police Rajnish Seth said.