An Indian soldier rescued nearly a week after he was buried by a deadly avalanche on the world's highest battleground was on Tuesday airlifted to Delhi in critical but stable condition, the army said.

Hanamanthappa Koppad spent six days buried after a massive block of ice fell onto his army post on the Siachen glacier, killing nine of his colleagues.

The rescue late on Monday came days after India said there was little hope of survivors from the disaster in the disputed Himalayan region of Kashmir.

General D. S. Hooda, who heads the Indian Army's northern command, called it a "miracle" as he described the huge challenges faced by the rescue team, operating at an altitude of 5,900 metres.

"It was not a typical soft snow avalanche. It was like a wall of rock-hard ice," he told AFP, describing how army rescuers used sniffer dogs and specialist radar to detect the buried soldiers.

"The effort went on day and night, except during two nights when blizzards hit the area.

"In the end, the whole effort paid off as a miracle when a survivor was pulled out. He is now being treated at a military hospital in Delhi."

The bodies of the other nine soldiers had now been retrieved, he said, declaring the rescue mission over.

Reports said the soldier, from the southern state of Karnataka, was found buried under nearly 25 feet (eight metres) of snow in temperatures of minus 45 degrees Celsius. He had survived thanks to an air pocket.

An estimated 8,000 soldiers have died on the glacier since 1984, almost all of them from avalanches, landslides, frostbite, altitude sickness or heart failure rather than combat.

In 2012, 140 Pakistani soldiers were killed at the high-altitude Gayari base in one of the worst disasters on the glacier.

Each side is estimated to deploy around 3,000 troops on the glacier, where winter temperatures plummet to minus 70 degrees Celsius, with blizzards gusting at speeds of 160 kilometres per hour.

The nuclear-armed neighbours fought a fierce battle over Siachen in 1987, though guns on the glacier have largely fallen silent since a peace process began in 2004.

The Kashmir region - of which Siachen is a part - is divided between Pakistan and India.