Rescuers struggled on Monday through mud and debris for a sixth day, as the number of missing people soared to nearly 4,500 since tsunami-like glacial floods roared down from the China-Nepal border, creating an “unimaginable” disaster.

The latest confirmed death toll surged above 900, with unidentified bodies buried in mass graves after DNA sampling.

The huge wave of freezing water, rocks and debris that smashed into villages and towns on Wednesday killed at least 939 people in Nepal and in Tibet, in China, with at least 17 bodies also pulled from rivers downstream in India.

Shibu Giri, a hydropower worker in Rasuwa, counts himself lucky to be alive.

A helicopter crew “tried to rescue me three times, but my body was stuck in the mud, up to my waist”, the 44-year-old Nepali told AFP.