Hundreds dead as over 2,000 remain missing in massive Nepal-Tibet flood

LONDON -- The death toll continues to climb two days after massive flash flooding obliterated parts of the Nepal-Tibet border region on Wednesday, with at least 543 bodies recovered across the region and over 2,000 people missing, authorities said Friday.

As search and rescue efforts continued in Nepal on Friday, authorities said at least 4,451 people had been injured and rescued, including 129 foreign nationals, and that 8,380 police personnel had been deployed to the region, according to the Nepal Police.

In Nepal, 1,924 people remained missing as of Friday, the National Disaster Risk Reduction and Management Authority confirmed, with 579 reported dead in Nepal and five in China.

Across the border in the Chinese region of Tibet, the state-run Xinhua News Agency reported Thursday that three people were confirmed killed and 558 others remained missing, citing local officials.

Among the missing are 90 Americans as of Friday, according to a State Department spokesperson. The department confirmed Friday that five Americans had been evacuated, up from three on Thursday.

The number of people considered missing has fluctuated significantly as recovery efforts have accelerated.

The flooding, captured in dramatic video footage, occurred in the northern Rasuwa district along the border with Tibet at around 8:40 a.m. local time Wednesday, authorities said. The flooding inundated areas along the Trishuli River, burying some buildings and damaging bridges and roadways.

The deadly wall of water that descended from the mountains on the border between Nepal and Tibet caused destruction at least 62 miles downriver from the border in Nepal, an ABC News analysis of verified video and satellite images shows.

The flood was reportedly triggered by a landslide about 12 miles northeast of the Rasuwagadhi border post along the Nepal-China frontier, according to Nepal Disaster Management.

A 5.2-magnitude landslide was registered in Nepal on Wednesday, according to the U.S. Geological Survey.

The seismic activity from the landslide was initially erroneously reported as a 4.4-magnitude earthquake, the agency said. It is unclear what triggered the landslide.

A geophysicist at Columbia University in New York told ABC News it appeared a landslide in the Himalayas took away a large glacier, or parts of one, in the mountain pass.

The initial location of the glacier was a cliff about 16,000 feet high. The debris avalanche, or landslide, slid down 6,000 feet on the slope, the USGS said.

While it will take time to determine how severe the landslide was, the USGS estimated that more than 100 million cubic meters of ice, rock and debris were displaced in the event, Ben Mirus, a research geologist with the agency, said Thursday.

Siddarth Venkatachalam, 30, told ABC News he had spoken to his mother just two or three hours before she went missing in the floods, as it was her birthday. Venkatachalam's mother was on a trip with his father and aunt, who are also among the Americans missing in Nepal.

"They were like excited for this trip," Venkatachalam said, visibly in shock. "It was like a spiritual, religious like trek they'd been looking forward to and preparing for."

The family said the three were located with Life360 on a bridge on the Tibetan border just before the flood.

In a statement, Nepal's Office of the Prime Minister expressed "deep sorrow" over the loss of life.

"Offering heartfelt tribute to all those who lost their lives in this natural disaster, it extends its sincere condolences to the bereaved families and relatives," the statement shared on social media said.

Meanwhile, the Nepali government on Thursday established an "Emergency Control Room ... to facilitate search, rescue, information verification and consular assistance in respect of foreign nationals affected by, missing in, or otherwise connected to the flood incident," according to Nepal's Ministry of Foreign Affairs.

U.S. President Donald Trump was asked about the Americans currently impacted by the deadly Nepal floods in the Oval Office Thursday. He called the disaster a "terrible thing" and said the U.S. is in active communication with Nepal's leadership and has offered to provide as much aid as necessary.

"That's a terrible thing. No, we are sending aid, and we've spoken to the leadership, and we let them know anything they want will happen," Trump said.

ABC News' Desiree Adib, Somayeh Malekian, Emily Chang, Will Gretzky, Charlotte Gardiner, Shannon Kingston, Ivan Pereira, Daniel Manzo, Joseph Simonetti, Dada Jovanovic, Meghan Mistry and Othon Leyva contributed to this report.