Construction fires are common in India due to a lack of fire -fighting equipment and routine contempt for safety regulations.
Last year, six people were killed in a fire in a hotel in Patna in the eastern state of Bihar.
The press agency Press Trust of India, which filmed images of flame in the Kolkata building, reported that “several people were seen to escape through the windows and narrow the edges of the building”.
Kolkata's Telegraph newspaper reported that at least one person died when “jumped from the terrace trying to escape” fire.
Verma said that the fire had been discussed and that “cooling operations are underway”.
Prime Minister Narendra Modi has offered his condolences to the families of people killed.
“Let the injured are recovering soon,” said his office in a statement.
Kolkata, a lively metropolis of more than 15 million people, is the capital of the state of Western Bengal, governed by the Party of the opposition Congress Trinamool.
