Americans among almost 400 tourists missing after Nepal flash flood

At least 18 people were killed and more than 380 listed as missing Wednesday in Nepal after flash flooding tore through valleys in the Himalayan country's northern border areas. At least three U.S. nationals were among the 291 foreigners listed as missing, according to Nepal's Tourism Board, citing information from tour companies.

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.

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.

In addition to the three Americans, the 291 foreign nationals reported missing included 12 British, 142 Indian, 17 Malaysian, four South African, eight South Korean, one Australian and one Dutch national. The nationalities of 111 other missing people had yet to be ascertained, authorities 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.