A seven-storeyed, unoccupied building collapsed here Friday morning, officials said.
The building was located in Vakola area of suburban Santacruz.
According to fire brigade, a large portion of the dilapidated building fell on an adjoining slum area where some people are believed to be injured.
According to BrihanMumbai Municipal Corporation Control Room, some two-three families are feared trapped in Catherine Chawl in the slum area.
Rescue operations are on and eight fire tenders have been rushed to the spot, officials said.