The Indian Army and state disaster management teams are carrying out rescue operations on the Gangtok-Natu La road near Milestone 15 where an avalanche struck, claiming seven lives.
The police and troops of the Trishakti Corps are also helping out in the search and rescue ops.
Several survivors have been rescued so far and the injured are being brought to the state capital Gangtok's hospital.
"Rescue and clearance operations are still on," a senior police official here said.
Nathula Pass is situated on the border with China and is a major tourist destination because of its scenic beauty.
The avalanche, which occurred early morning at the 14th milestone on Jawaharlal Nehru Marg, had trapped 25-30 tourists, according to defence sources.
"Swift rescue operations were launched by Border Roads Organisation and 22 people were rescued till now including 6 from a deep valley," they said.
Some 350 people and 80 vehicles, which were stranded on the road because of the snow blocking the road from Nathu La, were also brought back, officials said.
