India, Aug. 27 -- At water monitoring stations along Nepal's Trishuli river on Wednesday morning, levels rose by as much as nine metres in half-an-hour. It might have been a wall of mud, ice and rock that unraveled nearly 170km south through seven Nepali districts. On the Chinese side of the border, Gyirong in Tibet was struck by a linked mudslide, with state broadcaster CCTV reporting that some roads were buried under more than two metres of soil.

At least 180 people have been confirmed dead and close to 1,500 are missing in Nepal, with hundreds more unaccounted for in Tibet. Among those are foreigners and tourists from at least 29 countries, including India.

What was initially believed to have been a glacial lake rupture triggered by ...