Five people have died and 23 Indian Army personnel are missing in India's northeastern state of Sikkim after a cloudburst led to flash floods.

The flooding happened in the Teesta River in Lachen valley, Sikkim, due to a "sudden cloudburst" over Lhonak Lake in the northern part of the state, the Indian Army said in a statement. A cloudburst is a very sudden and destructive rainstorm.

River water levels rose very quickly, increasing to around 15-20 feet higher than normal, said the Army, which added that 41 of its vehicles were submerged under the resulting slush.

Five bodies have been recovered, according to a statement by the government of Sikkim. A search and rescue operation is ongoing and three people have been rescued.

At least three bridges have collapsed and about 420 people from two districts have been moved to relief camps, according to the government of Sikkim.

Flooding is not unusual in Sikkim, a state in the Himalayas, but scientists are clear that extreme weather such as storms is becoming more frequent and more intense as the human-caused climate crisis accelerates.