At least ten persons died and around 15 others were trapped under the debris of a tunnel that collapsed in India's northeastern state of Sikkim on Tuesday, confirmed a senior district official.

The incident was reported from the Namchi district. The tunnel belonged to the National Hydroelectric Power Corporation (NHPC).

"We have recovered 10 dead bodies, and efforts are on to find out the rest. We are told that nearly 15 persons are still trapped inside the tunnel. The fate of those trapped is uncertain as of now. Rescue work is on. It is a difficult task to go inside the tunnel as visibility is negligible there," said Additional District Magistrate Subash Ghimeray.

A methane gas explosion had triggered the tunnel's collapse, according to local media reports.

XINHUA