Nepali rescuers raced on Monday in a bid to free dozens of hydropower workers believed trapped in tunnels after devastating floods as search efforts entered a sixth day, officials said.

More than 100 people remain trapped in a hydropower tunnel in Nepal, while rescuers across the border in Tibet have been forced to withdraw as fears grow of renewed flooding.

Nepali army helicopter teams are striving to rescue approximately 100 individuals trapped in a tunnel at a hydropower project, overwhelmed by floods two days ago.