NEW DELHI - The death toll from Saturday's disaster on the outskirts of Chennai rose to 31. Officials said many more were still believed to be trapped in the debris.
Mr Karuna Sagar, a senior officer with the Tamil Nadu state police force, said they had managed to pull a survivor to safety on Tuesday afternoon as rescue workers toiled round the clock.
"We pulled out one young labourer from the debris on Tuesday afternoon. He was alive and in a healthy condition," Mr Sagar told AFP by phone. "Earlier, three people had been pulled out alive. One late at night and two others early this morning. They have all been taken to the hospital."
Mr Sagar said that a total of 31 people were now confirmed killed in the accident, with 27 others pulled out alive.
"We will continue with the operations until we are satisfied that there are no other survivors and all the debris has been cleared," he said. "We hope to find more people, but no one knows the exact number of people still feared trapped under the rubble."
Reports said that one of the survivors, a 27-year-old man named Mahesh, had indicated Tuesday that there were "several" people still alive under the mass of concrete, raising the hopes of rescuers and families.
Television footage showed rescuers wearing hard hats and masks carrying a survivor on a stretcher down a hill of debris to an ambulance.
Most victims were construction workers, who were reportedly in the building to collect their wages.
Emergency teams used mechanical diggers and heavy-cutting equipment to try and find more survivors in the ruins of what was a partially-built 11-storey complex.
Six people have been arrested so far on account of negligence, including the builder and his son, the architect of the residential tower and three others overseeing the construction.
The collapse in Tamil Nadu came only hours after a dilapidated apartment block crumbled in the capital New Delhi, killing 10 people including five children.
Building collapses are common in India. Lax regulations and the demand for cheap housing mean contractors sometimes use substandard materials or add unauthorised extra floors.
In September last year more than 50 people were crushed to death when a five-storey building collapsed in India's financial hub Mumbai.