A flooded street in Lachen Valley following a flash flood caused by intense rainfall in Sikkim, India, on Wednesday. AFP

However, some other media channels put the death toll at 8. According to a report one soldier has been rescued so far while search and rescue operation by the Army continued for the remaining 22 soldiers.

The northeastern state received 40.9 mm of rainfall between Tuesday and Wednesday morning, according to the India Meteorological Department (IMD) - almost five times its normal rate of 8.6 mm for this time of the year.

"So far, 10 bodies have been recovered from different locations. At least 82 more are missing and 22 people are injured, some of them seriously," Sikkim Chief Secretary VB Pathak told reporters.

A cloudburst - or an extreme amount of rain over a brief period of time - over Lhonak lake triggered the torrential flooding in the valley located about 150 km north of Gangtok near the border with China.

"Intense rain has led to this catastrophic situation in Sikkim where the rain has triggered a glacial lake outburst flood and damaged a dam and caused loss of life and caused further damage to roads and infrastructure," said Miriam Jackson, a senior cryosphere specialist at the Nepal-based International Centre for Integrated Mountain Development.

Heavy rainfall hampered the search for the Indian troops reported missing, with the capital city of Gangtok cut off by road, defence officials said.

"Twenty three personnel have been reported missing and some vehicles are reported submerged under the slush. Search operations are underway," a defence ministry spokesperson said.

India's weather department has warned of landslides and disruption to flights as heavy rain is predicted to continue over the next two days in some parts of Sikkim.

Jackson warned that such extreme events have become more frequent "as the climate continues to warm and takes us into unknown territory."

Agencies