KATHMANDU — The death toll from catastrophic flooding in Nepal and China has reached 1,019, with more than 4,400 people still missing as rescue crews work to reach communities cut off by the disaster, Al Jazeera reported.

In an update on Tuesday, Nepal's National Disaster Risk Reduction and Management Authority revised the number of deaths to 1,003 from 987, with 3,916 people missing, including 583 foreigners. Chinese authorities reported 16 deaths and 546 people still missing, including 261 foreigners, in their most recent update on Sunday.

The disaster began on 26 August high in the Himalayas, when a glacial collapse sent large volumes of rock, ice and meltwater into the valleys below, triggering powerful floods downstream. Scientists studying satellite imagery said the collapse appears to have involved the failure of bedrock beneath a glacier.

Hundreds feared trapped in tunnels

Hundreds of workers are feared to be trapped in tunnels at several damaged hydropower stations in Nepal, which have become the focus of rescue efforts.

Prime Minister Balendra Shah said 279 workers had been rescued from hydropower projects so far, at sites where authorities had initially estimated that more than 900 people were missing. More than 11,000 people have been rescued across the affected region, he said, and power and communication lines have been restored in some areas.

"Thousands of citizens have lost their homes, families, loved ones, and property," Shah said. "The government understands the immense pain they are enduring. The path ahead is to support them through this suffering and help them return to normal life through rehabilitation."

Road links to Nuwakot, one of the worst-hit districts, have been restored, easing rescue work and the distribution of relief supplies, he added. Police official Bipin Regmi told Reuters that a search team had recovered 24 bodies from a single house in Betrabati village in Nuwakot. "We are reaching new areas and recovering bodies," he said.

Reporting from the village of Dhunge, Al Jazeera's Jessica Washington said residents had told her that at least 250 homes were pushed into the floodwaters. "The real number could be much more; only a few buildings are still standing in such a deep state of disrepair," she said.

Aid and the hydropower question

Aid worth more than $42m has reached the country since the disaster, Shah said, and the government expects contributions to rise. India and China are assisting with rescue efforts, including building Bailey bridges to reach remote areas.

Nepal has seen a boom in hydropower projects since the turn of the century as the country sought to use its Himalayan water resources to address chronic power shortages and sell electricity to India. Such projects rely on tunnels to carry water through steep terrain, exploiting the sharp elevation drop between Himalayan rivers and powerhouses — the same tunnels now at the centre of the search.

Reporting attributed to Al Jazeera, the Associated Press and Reuters. Death and missing-person figures are official totals that continue to be revised.