Eight persons died on Wednesday after flash floods in the Teesta river triggered by a glacial lake outburst swept northern Sikkim’s Lachen valley and surrounding regions, PTI reported.

Officials said that five bodies have been recovered from the Golitar and Singtam region, while three washed up to North Bengal. They added that three persons have been rescued from Golitar.

Forty-nine people, including 23 Indian Army personnel, are missing in the flash floods from the Pakyang district, the Sikkim government said.

Due to heavy rains, the water level in Lhonak Lake rose and crossed the danger water mark early in the morning, the government said. This phenomenon is called a glacial outburst as Lhonak is a glacial lake.

The flash floods, which began around 1.30 am, then washed away the Teesta-III dam in Chunthang district, reported the Hindustan Times. It also led to camps and 41 vehicles getting submerged.

However, as of 1 pm on Wednesday, Central Water Commission said that the Teesta river was below the danger mark and the area around it was not flooded.

Defence officials said establishments along the valley had also been affected. A steel bridge at Singtam, known as the Indreni bridge, in Gangtok district has been completely washed away. The bridge is a very important connection over the Teesta river.

The Border Roads Organisation has launched rescue operations and 80 locals have been evacuated so far, defence officials said.

The National Disaster Response Force rescued seven persons from Singtam, reported ANI. Meanwhile, State Disaster Response Force rescued 25 people in Gangtok, the Sikkim government said. At least, 500 people have been moved to relief camps.

The state education department has ordered all schools in Mangan, Gangtok, Pakyong and Namchi districts to remain closed till October 8, reported PTI.

Sikkim Chief Minister Prem Singh Tamang, who visited flood-affected area of Singtam, urged citizens to remain vigilant and avoid unnecessary travel. “It is essential that we maintain composure and hope for a swift return to normalcy in our region,” he said in a tweet.

West Bengal Chief Minister Mamata Banerjee also urged citizens in north Bengal neighbouring Sikkim to remain vigilant.

“All steps have been taken to evacuate people in the districts of Kalimpong, Darjeeling and Jalpaiguri to safer places,” Banerjee said in a tweet. “Senior ministers of the state and senior IAS officers have been rushed to North Bengal to oversee rescue and relief operations. Close vigil is being kept to ensure no loss of life in this grave calamity.”