Nepal seeks specialist foreign help after devastating floods

Nepal has appealed for specialised international assistance following the catastrophic flooding that has killed more than 600 people across the Himalayan border region with China.

More than 2,000 people remain unaccounted for after a glacier collapse on Wednesday unleashed a torrent of rock, ice, mud and debris through mountain valleys in Nepal and China's Tibet region.

Entire towns have been levelled, while schools, hospitals, hydroelectric plants, roads and bridges have suffered extensive damage.

Nepal's Foreign Minister Shisir Khanal says the country can manage general search-and-rescue operations itself, but requires international expertise in areas including tunnel rescues, restoring transport and communications, identifying victims and DNA testing.

Officials say some people may be trapped inside tunnels at hydroelectric plants, where Nepal lacks the specialist equipment and expertise required for rescue operations.

Hospitals in some areas are also struggling to cope with the number of bodies being recovered. Many victims were swept downstream, with bodies found around 100 kilometres from the worst-hit areas.

Nepal has requested temporary bridges from neighbouring India and China after around two dozen bridges were destroyed.

Several countries, including India, China, the United States, Britain, Japan and South Korea, have offered assistance.

Nepalese officials say further international support is also likely to be needed for the reconstruction and rehabilitation of devastated communities.

Finance Minister Swarnim Wagle told Reuters on Saturday, Nepal needs $4 billion to $5 billion for rebuilding. "This is just an estimate. Loss and damage is being assessed," he said.