The fire that broke out in the GST Bhavan in Mazgaon earlier on Monday turned more severe and firefighting operation is underway, officials said.
"The level III fire has turned into a level IV fire. Firefighting operation is in progress using 40 to 50 breathing apparatus sets in a smoke-logged building. 14 fire engines are in operation," a fire department official said.
The fire had first broken out on the 7th floor of the building which then spread to the 8th floor.
No casualties or injuries have been reported so far. The reason for the fire is yet to be ascertained. More details are awaited.