Gangtok | Six tourists were killed and 11 others injured in a major avalanche in Sikkim's Nathu La area on Tuesday, police officials said here.

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.

Nathu La, one of the most important Himalayan passes in the country, is situated on the border with China and is a major tourist destination because of its scenic beauty. It is over 55 kilometres from Gangtok.

The avalanche, which occurred early morning at the 14th milestone on Jawaharlal Nehru Marg connecting Gangtok and Nathula, had trapped 25-30 tourists, according to defence sources.

"Swift rescue operations were launched by Border Roads Organisation (BRO) 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.

Nathu La, situated on the international border 14,450 feet above sea level, is one of the three open trading border posts between India and China.