No casualty was reported.
Ten fire tenders were pressed into service to douse the fire which broke out at 12, Pretoria Street building next to a school at around 12.50 pm, a senior officer of the Fire Department said.
Besides fire fighters, a couple of teams from Kolkata Police Disaster Management unit rushed to the rescue of inmates of the building, mostly office workers, breaking glass panes to release smoke from inside, he said.
"Our fire department officials worked quite efficiently and brought out everybody from the building. The cause of the fire is yet not known. Everything is under control now," Chatterjee said adding that there will be an investigation into the incident.