At least 236 shops were destroyed by a major fire at Asia's largest wholesale flower market in the commerical hub of Burrabazar in the city on Friday night.
Fire Brigade sources said 16 fire tenders have been sent to contain the blaze that started at around 8:30 pm at Jagannath Ghat beside Strand Road.
Police sources said a gas cylinder burst could have triggered the fire.
Strong wind from the Hoogly river helped the fire spread fast, City Police Commissioner Goutam Mohan Chakraborty said.
"The fire is devastating, and we are trying every possible means to bring it under control", he said.
More fire tenders were being sent to the spot, he added.
A large crowd has gathered at the spot and the police are having a trying time in cordoning them off.
As Jagannath Ghat is situated under the Howrah Bridge which connects Howrah and the metropolis, road traffic to and from the city has come to a halt in the area. Serpentine queues of buses, taxis and private cars could be seen on Brabourne Road and Strand Road.
Chakraborty said three fire tenders have been positioned near Howrah Bridge to prevenmt any damage to the bridge.