At least one person has been killed after a seven-storey residential building collapsed in Mumbai's western suburb of Vakola, local media reports.
Four persons have been rescued from the debris, NDTV reported on Friday.
Reuters news agency quoted Indian officials as saying that at least 10 people could still be trapped under the debris.
According to fire brigade personnel, the building, located in Yashwant Nagar near Grand Hyatt Hotel in Santa Cruz, came down around noon on an adjoining slum.
A team from the National Disaster Response Force (NDRF) is helping in rescue operations. Eight fire tenders are also present at the spot.
The building had already been condemned as unsafe when it crashed down into a huge pile of concrete slabs, rubble and dust, Disaster Response Force commander Alok Awasthi said.
"Our rough estimate is that there are around eight to 10 people feared trapped inside. Rescue operations are going on," Awasthi said.
Building collapses are common in India, where high demand for housing and lax regulations have encouraged some builders to cut corners, use substandard materials or add unauthorised extra floors.