It was confirmed that 18 people were killed Monday and 200 others were missing after an avalanche in the Himalayas caused a river to flood, inundating two power stations and eroding bridges and roads.

"There was a cloud of dust as the water gushed out. The ground shook like an earthquake," Om Agarwal, a resident of the area, told Indian TV.

On Monday, the state government of Uttarakhand announced that 18 bodies had been found, and Prime Minister Trivandra Singh Rawat said at least 200 people were still missing.

Most of the missing were working in the two power plants. Some were stuck in two tunnels blocked by floods, mud and rocks.

Rawat told reporters, "If this accident happened in the evening, after the end of working hours, the situation would not have been this bad because the workers at the two sites and their surroundings would have been at home."

Pius Rotella, a disaster management official, told AFP that 12 people were rescued from one of the tunnels on Sunday, but 25 to 35 others were still trapped in the second tunnel.

As the main road washed away, rescuers had to use ropes to reach the entrance. Also, emergency workers were using heavy machinery to remove tons of rocks.

"An area of up to 80 meters inside the tunnel has been cleared. It looks like there are still about 100 meters of debris that needs to be cleared," said Vivek Kumar Pandey, another disaster management official.

Hundreds of rescue workers resumed the search early Monday, including disaster response teams, the army and marine diving teams.

Dozens of mobile phone videos that were circulated on social media showed a massive flow of water through a narrow valley below the power plant, destroying roads and bridges.

"We were working 300 meters inside the tunnel," said Rajesh Kumar, 28, a survivor of the accident.

"Suddenly we heard whistling and screaming officials asking us to get out."

"We started running to try to get out, but the water poured in. It was like scenes from a Hollywood movie. We thought we would not survive," he told AFP.

Authorities initially said that the cause of the accident was the breakage of an ice mass in a river, but the cause may be a phenomenon called Lake Glacier Explosive Flood (GLF).

In recent years, glaciers in the region have been shrinking at a rapid pace due to climate change, but experts say building hydroelectric power plants could also be a factor.

In 2013, devastating monsoon floods in the state killed 6,000 people and led to calls for a review of development projects in Uttarakhand, which has a population of 10 million and is located on the borders of Tibet and Nepal.

Vimlindo Jha, who founded the Soisha Group, an environmental non-governmental organization, said the disaster is a "sad reminder" of the effects of climate change and the "unbalanced growth of roads, railways and power stations in environmentally fragile areas."

A study in 2019 showed that two-thirds of the world's Himalayan glaciers, the "third pole," could melt by the year 2100 if global emissions were not sharply reduced.

The region's glaciers are an important source of water for hundreds of millions of people, and they feed many of the world's most important river systems.