As many as 30 people, including 23 Army personnel, went missing in a sudden flash flood in Teesta River in North Sikkim’s Lachen Valley on Wednesday. There have been serious damages to the public property due to flash food triggered after the outburst of Lhonak Lake. At least six bridges built over the Teesta River between Chungthang and Rangpo have been washed away. Pictures and visuals shared on social media showed damaged roads and electricity poles as the flood wreck havoc in three districts of Sikkim.

Mangan (north Sikkim), Pakyong and Gangtok (east Sikkim) have been affected by the Teesta River flash flood. Mangan was among the worst hit districts. Officials have warned Teesta River is likely to cross the danger mark within a few hours and a flood alert has been sounded in low lying areas of Sikkim and Bengal.

The 414 km long Teesta River flows through rises in the Pauthunri Mountain and flows through Sikkim and West Bengal before entering Bangladesh. A flood alert has also been issued for some areas of Bangladesh as well.

Houses in the Lachen Valley were submerged and vehicles wept away in the flash flood. Authorities are yet to ascertain the exact number of casualties but they have confirmed seven civilians are missing.

The Army has issued a separate statement saying 23 of its personnel are also missing and a massive search and rescue operation is underway to locate them.

“Due to a sudden cloud burst over Lhonak Lake in North Sikkim, a flash flood occurred in Teesta River in Lachen Valley. Some army establishments along the valley have been affected and efforts are on to confirm details. 23 personnel have been reported missing and some vehicles are reported submerged under the slush. Search operations are underway,” Defence PRO, Guwahati said.

Meanwhile, the India Meteorological Department’s regional office in Gangtok has rejected the reports of cloudburst.  “The maximum rain received in north Sikkim in the last 24 hours was 39 mm. So, we can’t say it was a cloud burst,” said an IMD official.

When a small area receives at least 100 mm rain within an hour, it is considered cloudburst.