As water, concrete and debris stormed through the darkness, almost sweeping him off his feet, Ram Chandra tightly gripped onto one of the rungs studded into the roof of the tunnel he was working in on the banks of Nepal’s Trishuli river.

The Nepal Prime Minister's Office has posted a video showing hundreds rescued from a tunnel after they were trapped in the flood disaster.

Rescue teams say destruction from flash flood has made it difficult to even locate entry points of tunnel