The Sikkim government has decided to evacuate by road on Tuesday the tourists stranded in Lachung and other northern areas of the state, with poor weather ruling out chopper rescue.

Around 1,200 tourists, including foreign visitors, are stranded in Mangan, the northern district along the China border, following landslides and flash floods on Thursday that have damaged roads and bridges.

"It was initially planned to airlift the tourists, as after the flash floods last October. However, because of bad weather, it's not feasible to engage choppers. Therefore, the alternative option of evacuation by road has been planned for Tuesday,” a source in the state government said.

The tourists stuck in Lachung, a popular hotspot in north Sikkim, and neighbouring areas are to be brought in cars to Tung, around 18km from Mangan, the district headquarters.

"As there are multiple landslide zones from Tung to Mangan, they will be taken to Mangan on foot. From Mangan, vehicles will be arranged for their onward journey,” the source said.

Representatives of the Travel Agents Association of Sikkim (TAAS) and all travel agencies, particularly those that have customers stranded in north Sikkim, have been asked to reach Mangan on Monday.

"From Mangan, the travel agents who have sent tourists to north Sikkim will have the responsibility for further movement of the tourists.... If any travel agency ignores the directions, steps will be taken against it," a TAAS representative said.

The tourists stuck in Mangan are facing hardship because of disruptions in power supply and the telecommunications network. "Around 360 of them are staying at a gurudwara in Chungthang. The gurudwara authorities have provided them with food and shelter,” a source said.

Samrat Sanyal, general secretary of the Himalayan Hospitality & Tourism Development Network, an apex body of tourism stakeholders in the region, said it was important that the evacuation of the tourists began on Monday.

“Four days have passed and they are still stuck in north Sikkim. Since it is not possible to use choppers unless the weather improves, it is pertinent to work on alternative options,” Sanyal said. “We hope a section of tourists will reach Mangan soon. We will extend the necessary help to them.”

As monsoon showers continue in Sikkim and sub-Himalayan Bengal, fresh landslides have damaged some stretches along NH10, the principal highway that connects Sikkim and Kalimpong with Siliguri and the rest of the country.

"The Kalimpong district administration has advised drivers not to take NH10 and instead travel along the Algara-Lava route to Siliguri and vice versa. As the rain has not stopped, there is always a risk of landslides or boulders falling on the road,” an official said.

With Sikkim-bound heavy vehicles forced to make detours since Thursday, bringing essential supplies to the state is taking more time.

On Sunday, the state food and civil supplies department formed a team "to check the stock of LPG cylinders and the inventory of essential items", a source said.

"Retailers and wholesalers have been cautioned not to hoard essential items or raise food prices," the source added.

Weather experts at the regional Met office in Gangtok said an alert had been sounded against heavy to very heavy rainfall (70mm to 200mm) in the Mangan and Namchi districts in the next 24 hours.

“The southwest monsoon is active over the region and is causing regular downpours,” an expert said.