More than 15 workers were feared trapped on Tuesday after a blast caused by a suspected gas leak in a tunnel being built for a hydroelectric project in India's rugged northeastern state of Sikkim that killed nine, officials said.
Monday's incident took place at state-owned power firm NHPC's project on the Teesta river in the village of Samardung, district official Subash Ghimirey told Reuters.
"The incident was caused by a possible natural gas blast but we cannot say for sure yet," said state disaster management official Rajiv Roka. "Nine bodies have been recovered - the bodies are charred, so it suggests there was a blast."
Survival chances for the rest were slim, he warned, as rescuers hunting for those trapped had difficulty breathing in the tunnel, making the task difficult.
At least 25 project workers and officials were trapped in the tunnel, the state government said on its Facebook page, citing information from NHPC. This figure includes the nine retrieved bodies.
An NHPC spokesperson did not immediately respond to a request for comment from Reuters.
Rescuers wearing orange hazard suits unloaded oxygen cylinders, ropes and other emergency equipment from a vehicle in photographs on the state government's Facebook page.