More than 60 people have been crushed to death on the outskirts of Mumbai after a building collapsed while under construction, with many victims believed to be labourers living at the site.
A section of the seven-storey building in Thane, a suburb of Mumbai, collapsed late on Thursday evening before the entire structure came down, a senior officer said on Friday.
Al Jazeera's Sohail Rahman, reporting from New Delhi, said 50 people were injured and some were in a critical condition.
The injured have been taken to at least five hospitals in the district of about 1.5 million people, Rahman said.
Television coverage of the accident shows people helping with the rescue through the night.
Our correspondent said that authorities are still looking for the contractor of the building, which is reported to be constructed "illegally" on forestland.
Teams from the National Disaster Response Force and other rescue workers were trying to clear the debris from the site amid fears there may be more people trapped in the twisted pile of of concrete and steel.
Our correspondent said the next 48 hours would be critical, as rescuers hoped to find survivors.
National Disaster Management Authority volunteers managed to rescue an elderly woman from the collapsed building late on Friday.
She had been trapped for several hours under the debris.
The victims were workers and members of their families who were living in some of the still-unfinished areas of the building.
The Hindustan Times daily said the builders may have flouted norms.
"Seven floors were built in merely three to four months. It was bound to collapse due to the inferior construction material used by the builders," the paper quoted the local head of the disaster management cell as saying.
Building collapses are a common occurrence in India, where a booming economy has led to a mushrooming of multi-storey structures which are often unauthorised and flout safety laws.
Two years ago, 66 people were killed and 80 were injured when a building collapsed in Delhi.
"India has a very stringent and tough building regulations, but many get through the cracks," Al Jazeera's Rahman said.
"It's very difficult to try and adhere to the building regulations, and also police it".