The number of people missing in Nepal and China surpassed 2,400 Friday, underscoring the scale of the disaster days after a tsunami-like wall of water and debris swept away villages and killed hundreds.
Rescuers were battling through mud even as the threat of new floods loomed, with emergency teams recovering 586 bodies so far – and some of the dead swept downstream as far away as India.
The new figures came as Nepal's disaster authority added 933 hydropower workers to a missing persons list already including trekkers and pilgrims to Tibet's sacred Mount Kailash.
Read moreRescuers grapple with mountain of challenges after the Nepal-Tibet floods
Relatives have crowded hospitals in Nepal's capital in a painful hunt for their loved ones, with posters on the walls bearing photos and names of the missing.
"Today is the third day and we don't know anything. Hopefully he is in a safe place," Samjhana Thing, 27, told reporters referring to her brother. "We lost everything. He is our everything."
The US Geological Survey said the disaster – the deadliest for Nepal since a 2015 earthquake – was caused by a glacial collapse that triggered a vast flow of icy debris.
The deluge of ice and mud also caused huge lakes to form, and one of these formations has become a direct threat to emergency workers scouring the region for survivors.
Nepali police urged all rescuers to "immediately move to a safe location", saying it had received information that "a water dam has burst again on the Tibetan side".
In Tibet, China was forced to suspend its rescue operation at the hardest-hit area of Gyirong over the risk of renewed flooding on Friday, before saying the threat had eased.
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State broadcaster CCTV reported that a lake formed by immense piles of debris began overflowing towards where rescue teams were headed, but later said the water level of the pool had dropped.
Rescue operations were therefore "proceeding in an orderly manner", it added.
Chinese President Xi Jinping, who chaired a meeting on rescue efforts, offered Beijing's help to Nepal's emergency operations.
'All swept away'
Emergency teams had been racing to retrieve survivors from affected zones, where the widespread devastation meant food and water supplies were running out.
The Nepali military located people trapped in the tunnel of Trishuli 3A hydropower project, where they were working to find a way in to extract the survivors.
"Two helicopters have been dispatched but it is challenging because it is tough to even locate the entry points of the tunnel," army spokesman Raja Ram Basnet told reporters.
Some 350 workers and residents have been brought to safety from the site, he added, but efforts were ongoing to rescue more than 100 people trapped in the same area.
Read more'Ran for our lives': Flood survivors recount terrifying escape from Nepal-Tibet disaster
Workers rescued from other dam projects along the Trishuli valley described a disaster that unfolded with terrifying speed.
Buddha Tamang told reporters he survived only because he was inside a tunnel at the dam where he worked when the flood struck.
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"The senior officers working on the other side, they were all swept away," Tamang, who was airlifted on Thursday after being marooned for more than 24 hours, told reporters.
'I just want my son back'
Survivors in a makeshift Nepali hospital endured an agonising wait for news of their missing loved ones.
Kula Priya, whose eldest son is missing, said she had lost everything when the wave of mud and water swept in.
"I don't care for wealth. I just want my son back. If any of you could rescue my son, please do it for me," she told reporters.
Nepal reported a death toll of 579 people on Friday.
There are 1,924 people, including 517 foreigners, who are out of contact in Nepal, the disaster authority said. The previous missing figure was 977.
Read moreHundreds of foreign nationals missing in wake of Nepal-Tibet landslides
In India, authorities said they had recovered seven bodies from rivers flowing from Nepal, believed to be flood victims.
Across the border in Tibet, which is largely inaccessible to foreign journalists and where the only sources of information are Chinese authorities – seven have died and 554 remain missing, the state Xinhua news agency reported early Saturday.
Authorities also said they had evacuated 555 stranded tourists and 499 Chinese residents from Tibet.
Pilgrimage route
Scores of Hindu devotees from across the world are among those missing on the border, as many were on a pilgrimage to Tibet's Mount Kailash.
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Sivaranjani Muthunathan was travelling by bus with 56 others towards the Chinese border when they became stuck in what they thought was a traffic jam.
"Then there was fog, smoke, something that seemed to suddenly engulf us," Muthunathan, 46, told reporters on Friday, showing a phone video she recorded of a torrent surging towards her.
"One by one, we also climbed out through the driver's side," then scrambled up a hill, she said.
(the broadcaster with AFP)
