The accident occurred Saturday in the state of Telangana after a sudden inflow of water and soil caused a part of the tunnel to cave in.

“Chances of survival I can’t predict. (But) chances are not that good,” state tourism minister Jupally Krishna Rao told reporters.

Rao said 42 workers swam to safety shortly after the collapse, adding that rescuers had called out to trapped workers through the rubble but not received any response.

He said rescue teams were working around the clock to remove the debris and another 100m were left to be cleared.

“We are not sparing any effort,” Rao said.

Accidents on large infrastructure construction sites are common in India.

In 2023, 41 Indian workers were rescued after a marathon 17-day operation helped pull them out of a partly collapsed Himalayan road tunnel in the northern state of Uttarakhand.