At least 15 Indian workers trapped after tunnel blast kills 10

Rescue operation underway in Sikkim state where incident took place at a under-construction tunnel

Fifteen Indian workers were feared ‌trapped on Tuesday after a blast caused by a suspected gas ‌leak in a tunnel ⁠at ​a hydroelectric project ​in the rugged state ‌of Sikkim killed ten, ​authorities said.

Monday's incident took place at state-owned National Hydroelectric Power Corp Ltd's ⁠project on the Teesta river in the northeastern ‌state's village of Samardung, district official Subash Ghimirey told Reuters.

A sudden burst of gas suspected ⁠to be methane ⁠trapped or embedded in ​rocks in ‌the tunnel caused an explosion that sent out dense fumes and toxic gas, NHPC said in a statement. * Survival chances for the trapped workers were slim, state disaster ⁠management official Rajiv Roka said, as rescuers had ⁠to battle the fumes, making their task difficult. At least 25 project workers and officials were trapped in the tunnel, NHPC said, a tally that includes the 10 bodies retrieved.

Read: India youth group says protest to continue after Delhi clashes injure 180

Photographs on the ⁠state government's Facebook page showed rescuers ​wearing orange hazard suits unloading oxygen cylinders,

ropes and other emergency equipment from a vehicle.

Modi assured the state government of “every possible assistance from the government of India to support the rescue efforts and provide relief to those impacted by the tragedy”.

According to the government, rescue operations are being carried out on a war footing by multiple agencies.

“Specialised teams are also assisting in the operation, working tirelessly to evacuate the bodies of the remaining workers trapped inside the tunnel,” the statement noted.