Sikkim flash floods kill 22, leave trail of destruction | In pictures.

At least 22 people, including four Army personnel, died and over 100 remained missing following a cloudburst over Lhonak Lake in north Sikkim district that triggered flash floods in the region earlier this week.

The devastating flash floods in Sikkim after a sudden glacial lake burst on Wednesday claimed several lives, causing widespread damage as roads, bridges, and homes were washed away. A sudden cloud burst over Lhonak Lake in North Sikkim had resulted in a flash flood in the Teesta River in Lachen valley, which was compounded by the release of water from a dam.

The flash flood led to the swelling of the river Teesta, sweeping away several houses in towns and villages and dozens of people, including Army personnel. The Teesta River took a furious form, and part of the state's biggest hydropower project, Sikkim Urja, was washed away, escalating the situation.

Teams of the Indian Army and the NDRF Army were working their way through slushy earth and fast-flowing water in the Teesta river basin and downstream north Bengal for the third day in search of those who were swept away and still missing, officials told PTI. The Army recovered three vehicles from the debris in the basin of the river Teesta. These vehicles were washed away by flash flood in Bardang.

The flood also destroyed 13 bridges in the state, with eight bridges getting washed away in Mangan district alone. Three bridges were destroyed in Gangtok and two in Namchi. Chungthang town bore the maximum brunt of the flood with 80 per cent of it being severely affected. NH-10, considered the lifeline of the state, sustained extensive damage at several places.

A total of 103 people were missing after the incident. Of them, 59 people were reported missing in Pakyong, 22 in Gangtok, 17 in Mangan and five in Namchi. A survey is being carried out by all agencies to assess the damage and plan restoration of road connectivity, the Sikkim State Disaster Management Authority (SSDMA) said in its latest bulletin.

The calamity affected over 22,000 people. So far, 2,411 people have been evacuated and accommodated at relief camps. The Indian Army is providing assistance in terms of food, medical aid and extending communication facility to civilians and tourists stranded in North Sikkim. Meanwhile, in West Bengal's Jalpaiguri, two people were killed while four others were injured after an Army mortar shell flowing through the swollen river Teesta exploded.