Sunrise scenery of the Himalayas is seen from Poonhill in Myagdi District, Nepal, Feb. 15, 2020. Poonhill is a popular spot along the trekking routes in the Annapurna region among tourists. (Xinhua/Zhou Shengping)

As many as 150 people were feared dead in northern India after a Himalayan glacier broke and crashed into a dam early on Sunday, with floods forcing the evacuation of villages downstream.

"The actual number has not been confirmed yet," but 100 to 150 people were feared dead, Om Prakash, chief secretary of Uttarakhand state where the incident occurred, told Reuters.

A witness reported a wall of dust, rock and water as an avalanche roared down a river valley.

"It came very fast, there was no time to alert anyone," Sanjay Singh Rana, who lives on the upper reaches of Raini village, told Reuters by phone. "I felt that even we would be swept away."

Locals fear that people working at a nearby hydropower project had been swept away, as well as villagers roaming near the river looking for firewood or grazing their cattle, Rana said. "We have no idea how many people are missing."

Prime Minister Narendra Modi said he was closely monitoring the situation.

"India stands with Uttarakhand and the nation prays for everyone's safety there," he said on Twitter after speaking with the state chief minister.

India's air force was being readied to help with rescue operations, the federal government said, while Home Minister Amit Shah said disaster-response teams were being airlifted in to help with relief and rescue.

"All the concerned officers are working on a war footing," Shah said on Twitter, referring to Uttarakhand by its nickname, the Hindi term for "land of the gods."

Reuters