The death toll in the five-storey building collapse in Mumbai's Bandra area raised six by Thursday evening.
Earlier, a person died and three others were injured.
The building was located in Behrampada slum of Bandra East. Six-seven people are feared to be trapped under the debris. A girl was rescued and three injured were taken to a hospital.
Fire department officials say the building was evacuated before it fell down.
Five fire tenders and two ambulances have reached the site of the collapse. An NDRF team has also reached.