At least six people have been killed this week and around 2,000 tourists stranded in India's Himalayan state of Sikkim in landslides and floods after incessant rainfall, officials said on Friday.

Another four people have been killed in Nepal's Taplejung district, which borders Sikkim, after a landslide following rains swept away the house in which they were sleeping, officials there said.

Heavy rains triggered landslides at several locations in Mangan district, which covers north Sikkim and lies about 100 km (60 miles) north of the state capital Gangtok, the local government of the northeastern Indian state said.

"It's been raining continuously for 36 hours. The road to north Sikkim has been damaged in multiple locations, snapping connection to the district," said Hem Kumar Chettri, the district magistrate of Mangan.

"The stranded tourists are all safe but we have not been able to evacuate them because of the damage," he said, adding that 11 of them were foreign nationals.

The small Buddhist state of 650,000 people, wedged between Bhutan, China and Nepal, is a popular tourist destination but also faces natural disasters caused by extreme weather events in the Himalayas.

At least 179 people died last year in Sikkim when a Himalayan glacial lake outburst triggered floods.

Personnel and machinery have been deployed to fix the road, Chettri said, adding that the damage was "extensive" and repair will take some time. About 50 houses have been partly or fully damaged by the rains and people have been take to a relief camp.

While eastern parts of Nepal have been lashed by heavy rains, the Himalayan country's western areas are facing one of the hottest seasons, weather officials said.