At least 160 people were killed in Nepal and more than 400, most of them foreigners, were listed as missing on Wednesday after flash flooding tore through valleys in the Himalayan country's northern border areas, according to authorities. 

The flash floods decimated villages, slamming into houses, roads, bridges and power plants. Videos broadcast by regional news outlets and posted on social media show violent torrents of water surging through valleys and mountain passes, tearing down bridges and dams and sweeping away buildings.

The Nepali police confirmed that at least 157 bodies were recovered following "devastating floods," but there was no word on the nationalities of the victims. Chinese state media reported "major casualties" from a mudslide at a Tibet border hub, including three dead.

Dozens of U.S. nationals were among the 341 foreigners listed as missing, according to Nepal's Tourism Board, citing information from tour companies. 

Hikmat Singh Ayer, CEO and senior director of Nepal's Tourism Board, told CBS News that 403 people were unaccounted for after the flooding. He said that among the missing foreign nationals are 33 Americans, 34 Australians, 24 Canadians, 4 Germans, 19 Malaysians and one Israeli. 

A sudden surge of water Wednesday morning in the Bhote Koshi River, in the country's northern Rasuwa district north of capital Kathmandu, quickly affected the neighboring Nuwakot and Dhading districts. 

Nepali President Ramachandra Paudel said he was "extremely saddened" by the "loss of lives and property caused by the sudden flood."

He called on the government, political parties, agencies and the general public to intensify rescue and relief efforts. 

"There could be heavy casualties or loss of property," district administrator Narendra Pariyar was quoted as saying by Reuters. He has also urged people living along the banks of the Bhote Koshi River to move to higher ground.

Nepal's mountainous terrain, dotted with deep valleys and narrow gorges, makes rescue and relief operations challenging. Helicopters could not land in the affected areas of Syapru Besi and Timure, Reuters said. 

Most of the missing foreigners were on trips organized by tourism and travel companies. 

The flash flood was caused by an earthquake that triggered a large landslide, which blocked the Bhote Koshi River, according to Nepal's Foreign Minister Shishir Khanal.

The Nepal Electricity Authority (NEA) confirmed that six of its major hydropower and transmission facilities were damaged in the flooding.  

"We do not exactly know the extent of damage, but the flood is big, and it could have damaged many settlements," Nepal Police spokesman Abi Narayan Kafle told the French news agency AFP. "We have alerted people who are staying near the riverside to relocate ... and deployed all our resources."

"Work has started to take necessary steps in coordination with the medical team, scouts, and Red Cross," Nepal's Prime Minister Balen Shah wrote in a social media post. 

India's government ordered authorities in states along the Nepal border to be on high alert.

AFP contributed to this report.

In:

• Rescue
• Nepal
• Breaking News
• Death
• Himalayas
• Asia
• Flooding
• Earthquake
• Flash Flooding