More than 2,500 tourists, many of them from Calcutta, were stranded along the route to Nathu-la and Changu Lake in east Sikkim on Friday after heavy snowfall made returning to Gangtok perilous for vehicles skidding on ice and slime.

The army took the tourists to nearby camps, where they were provided medical attention, food and accommodation. After the ice melted and excavators cleared the roads on Saturday, they were sent to Gangtok in groups. By late afternoon, all of them were back in the state capital.

“Sudden snowfall between 17th Mile and Nathu-la had left the tourists stranded. We engaged our quick-response teams, medical teams and other personnel to rescue over 2,500 tourists, including women and children,” a senior army officer said.

“They were taken to our camps and given all possible help. On Saturday, we gradually sent them down to Gangtok.”

Army sources said 400-odd tourist vehicles could not return to Gangtok on Friday. While 1,500 tourists were accommodated at 17th Mile, the rest were sent to camps at 13th Mile. Both camps are located along the route to Gangtok.

Several tourists had symptoms of high-altitude sickness typical of 11,000 feet above sea level or higher. Many others complained of numbness and nausea. “Around 90 people were found to be sick and shifted to Gangtok in 10 army vehicles and three ambulances. The task of shifting the rest began around 11.50am,” an army officer said.

Most of the tourists said they would have been in greater trouble but for the army’s prompt response. “We were in a fix as our vehicle could not move on the ice-laced road. It was also getting dark. At that point, a group of soldiers came and guided us to their camps,” said Sarvesh Sharma, a tourist from Delhi. “We would have had to spend the night in the open had help not arrived. The army emptied their barracks to accommodate us. We cannot thank them enough.”

Debasish Sarkar, a tourist from Bankura, said returning safely to Gangtok had looked almost impossible at one point. “It was extremely cold. We later learnt that the temperature had dropped below zero at night. Without the army’s help, it would have been tough for us to weather the cold and return safely to Gangtok….I had seen and read about the human face of the army; now I have seen it first-hand.”

Tourists wanting to visit Nathu-la, Changu Lake and parts of north Sikkim on Saturday were denied permits because it was unsafe to travel, sources in the administration said.

Additional reporting by Rajeev Ravidas in Gangtok