Rescuers in Nepal and China battled deep mud, rising rivers and a newly formed lake Sunday to search for thousands missing after a wall of water and debris swept through the Himalayas, engulfing entire villages.

Latest figures from both countries put the number of missing at 3,048, including hundreds of foreigners. Authorities confirmed 768 deaths, and some bodies were reportedly swept downstream as far away as India.

Nepal said it began the grim task of burying some of the hundreds of bodies Sunday, after taking DNA samples to allow families to reclaim them and perform traditional funeral rites once identified.

A glacial collapse caused the disaster, which struck the China-Nepal border Wednesday morning, sending a wall of water and debris downstream, the U.S. Geological Survey said.

Nepali army troops and engineers also drilled through debris Sunday toward hydropower workers believed trapped in a tunnel at the Trishuli 3A hydroelectric site in the Himalayan river valley after inserting a pipe into the passage.

"They have started sending air through the small opening," Nepali Home Minister Sudan Gurung said in a statement.

Overnight rain and rising river waters hampered efforts earlier Sunday, filling the excavation area with water before conditions eased, the Nepal army said.

Nepal's disaster authority listed 933 hydropower workers among the missing in an area home to vast energy infrastructure projects.

Chinese rescuers near the Tibet border port hit by a deadly mudslide moved to a safe location Sunday after a landslide formed a new lake, state media reported.

China's state news agency Xinhua reported Sunday that experts said a glacier on the southern slope of Lirung Peak in Nepal fractured, triggering an ice-rock avalanche.

The torrent plummeted, forming a massive debris flow that traveled more than 20 kilometers (12 miles) before crashing into Gyirong Port.

"The sudden glacial collapse and flash flood is a devastating reminder of how fragile these mountain environments can be," U.N. climate chief Simon Stiell said in a statement.

'Nothing left'

Survivors face an agonizing wait to learn the fate of missing relatives and the prospect of rebuilding their lives from nothing.

"All the settlements near the river were swept away," resident Buddhi Ram Dangol told Agence France-Presse (AFP) in Nepal's Nuwakot district.

"There is nothing left."

Worried relatives crowded around lists of rescued people pasted on a wall at an army base serving as a rescue hub in the district capital Bidur.

Nepal's disaster authority said Sunday 592 foreigners, including trekkers and Hindu pilgrims to Tibet's sacred Mount Kailash, were among the missing.

The Isha Foundation, led by Indian guru Sadhguru, said in an Instagram post Saturday that 80 members were on a group trip in the area.

"At this time, there seems to be no encouraging indications of survivors at the immigration office area," it said.

'Enormous' trauma

The United States and Canada said they would provide $3.6 million each in humanitarian aid to Nepal.

The U.K. has offered $6.8 million, while the U.N. released $2.5 million in emergency funding. The European Union, the International Federation of Red Cross and Red Crescent Societies and others also pledged aid.

Nepal's economy is already under pressure, with limited resources to respond to a disaster of this scale. Foreign Minister Shisir Khanal said the reconstruction bill could run into "billions of dollars."

He appealed for specialized assistance, including heavy-lift drones and technology to help locate trapped people.

Malaysia said it would send search-and-rescue specialists to assist.

Khanal also called for forensic testing kits to identify corpses and freezer units to store them, saying bodies exposed to water could decompose at a faster rate.

The deluge of ice and mud caused huge lakes, and one of those formations has become a risk for further floods.

The Chinese and Nepali foreign ministers spoke Saturday and discussed sharing satellite and hydrological data, both sides said.

In Tibet, where Chinese authorities are the only source of information, authorities paused rescue operations at the hardest-hit area of Gyirong because of the risk of more flooding from a newly formed lake.

However, state broadcaster CCTV said late Saturday that the lake was "discharging naturally" and had been "essentially drained," citing China's Water Resources Ministry.

2,141 rescuers were near the Gyirong site, the Xinhua state news agency said.

Pilgrimage route

Nepal reported a death toll of 752 Sunday, with 2,502 unaccounted for.

Across the border in Tibet, 16 people died and 546 remain missing, CCTV reported.

Authorities also said they evacuated 555 stranded tourists and 499 Chinese residents from Tibet.

In India, officials said they recovered seven bodies from rivers flowing from Nepal, believed to be flood victims.