Police in southern India have detained five construction company officials as rescuers search for dozens of workers believed buried in the rubble of a building that collapsed during monsoon rains.
It was one of two weekend building collapses that killed at least 22 people. Rescuers warn many more bodies could be found.
Nearly 90 contract workers are believed to have been in the basement of the 11-storey structure to collect their wages when it collapsed on the outskirts of Chennai, the capital of Tamil Nadu state.
Police said 31 had been pulled out so far, four were pronounced dead at the site and another seven died shortly after arrival at hospital.
The total number of workers trapped is unknown but there were reports that up to 100 people could remain inside.
Rescuers said they could hear voices in the debris, said TS Sridhar, the disaster management agency commissioner.
Officials were last night using gas cutters, iron rods and shovels after cranes lifted concrete blocks to get to the survivors.
“Removing debris is a major challenge. It may take two, three days to clear,” said SP Selvam, who is heading up the rescue operation.
Police said two directors, two engineers and one supervisor of the construction company, Prime Sristi, were detained for questioning as authorities began investigating the collapse.
Balaguru, one of the builders, said the structure collapsed possibly due to the impact of lightning.
“Usually, once the construction gets over we install the equipment to prevent the building from a thunder strike. It was nearing completion,” the Press Trust of India news agency quoted Balaguru, who uses one name, as saying.
Earlier, 11 people died and one survivor was being treated in hospital after a four-storey, 50-year-old structure toppled in an area of New Delhi inhabited by the poor, said fire service officer Praveer Haldiar.
Most homes in that part of the capital were built without permission and using substandard materials, police officer Madhur Verma said.
A police investigation has also been launched.
In April last year, 74 people were killed when an eight-storey building being constructed illegally in the Mumbai suburb of Thane in western Maharashtra state caved in.
It was the worst building collapse in the country in decades.
India has seen frequent building collapses, many blamed on lax safety and substandard materials.
The latest incidents have once again put the spotlight on the need for better regulation of construction in the country.
While some collapses are a result of poor quality material being used, others have been because the buildings were simply too old and residents refused to leave despite them being labelled as dangerous to live in.
Corruption is also a factor because, in many cases, changes to the building’s structure such as adding extra floors, or breaking down walls, which might make it vulnerable, are permitted by authorities that have been found to have accepted bribes.