The death toll touched 45 on Friday in an under construction building collapse on Thursday evening at Thane on the outskirts of Mumbai even as the dead included women and 11 children, officials and media reports said.
Maharashtra Chief Minister Prithviraj Chavan on Friday visited the site of the collapse even as rescue operation continued with the help of National Disaster Response Force (NDRF).
The death toll rose on Friday as more bodies were recovered from the debris on Friday morning, said the police.
About 70 others were injured after the seven-storey building collapsed around 6.30 pm on Thursday at Shil Dhaigar locality in Thane.
National Disaster Response Force (NDRF) Director General (DG) PM Nair on Friday said: "We have been able to rescue 40 lives so far. We got 36 dead bodies."
Some of the deceased men were workers at the construction site.
Reports said the building was an illegal construction that took place within two months with poor building material.
There was a pregnant woman, identified as Shakila Imran Siddiqui, among the deceased, said the police. The other bodies have not been identified so far.
Asked about the duration of rescue operation, Mumbai Deputy Chief Fire Officer P S Rahandale said: "This is going to be a prolonged rescue operation because there is a lot of debris over there. And apart from that, there are lives inside."
According to reports, several people are still feared trapped under the debris as rescue work continued on Friday under the supervision of Municipal Commissioner RA Rajeev and District Collector P Velarasu.
Meanwhile, the police said they have registered a case under Section 304 (culpable homicide not amounting to murder) of Indian Penal Code against builders Jamil Qureshi and Salim Shaikh who are untraceable since the accident happened.
Thane Commissioner of Police KP Raghuvanshi said: "It was a weak building. We have filed a case under Section 304 against the builders and we are searching them. We hope to arrest them soon."
According to reports, at least 28 families were living in that building without occupancy certificates even though construction was underway.
Confirming the news, Mumbai Suburban District Deputy Collector Manoj Gohad said the building was unauthorised and had been occupied up to at least the fourth floor.
More than 12 fire engines and over 24 ambulances have been stationed at the site.
The injured were admitted to various hospitals including Thane Civil Hospital, Chhattrapati Shivaji Maharaj (CSM) Hospital, Kalsekar Hospital, Lokmanya Tilak Hospital and JJ Hospital.
Meanwhile a political blame game between the Shiv Sena (which is in charge in the Thane Municipal Corporation) and the state´s ruling NCP-Congress alliance has begun over the responsibility of the tragedy.