The mountaineers were led by a highly experienced British climber. (Reuters)

Highlights Eight mountain climbers went missing on Nanda Devi mountain

Military helicopters involved in rescue ops found five bodies yesterday

The group changed their plans without permission, an official said

Eight climbers believed to be dead on a treacherous mountain in Uttarakhand "knowingly risked" their lives by changing their plans without permission, an official said Tuesday.

Military helicopters involved in a major search for the four Britons, two Americans, an Australian and an Indian on Monday spotted five bodies on the Nanda Devi mountain.

The group, led by highly experienced British climber Martin Moran, had been given permission last month to scale the eastern peak of the mountain.

But Moran's mountaineering company announced on Facebook on May 22 after reaching a second base camp that they planned to attempt "an unclimbed peak" 6,477 metres (21,250 feet) high.

"This mountain range is more difficult to scale than Mount Everest. They knowingly risked their lives after changing their plans without informing the authorities," an official in Uttarakhand, where the mountains range is located, told AFP.

"The permission was granted for Nanda Devi east and any diversion is illegal. We were completely unaware of their changed plan and that turned fatal," he said, preferring to remain anonymous.

Surendar S. Panwar from local trekking operator Cosmos Tour and Expedition, said that Moran was highly experienced and had previously climbed in the area.

"It is quite surprising how a qualified mountaineer like him made a mistake," Panwar told AFP.

Dangerous operation

Vijay Kumar Jogdande, a local magistrate, told AFP on Tuesday that a plan was being devised to retrieve the bodies in what would be a dangerous operation due to the risk of avalanches and bad weather.

"We are meeting today to chalk out a plan to retrieve the bodies," said Jogdnade. Officials were looking at the possibility of sending a team on foot or airlifting the bodies.

He said the aerial pictures shot on Monday showed four bodies together and another lying buried at a distance on a ridge that was swept by an avalanche. Three more were believed to be nearby.

Officials said a total of 12 climbers had set out from Munsiyari in Pithoragarh but they separated into two groups a week later after reaching the Nanda Devi east base camp.

The groups communicated last on May 26, a day before heavy snowfall and massive avalanches hit the heights.

Later the eight failed to report back to the base camp, first prompting a search by the other four climbers followed by a massive search by authorities after a porter sounded the alarm.

Hundreds of climbers from across the world visit India to scale mountains across the Himalayan chain, and the peaks in Nanda Devi sanctuary are considered the toughest to scale.

The first successful ascent of the Nanda Devi summit was in 1936.

India has 10 peaks above 7,000 metres, including Kangchenjunga -- the world's third highest -- sandwiched between India and Nepal.

The latest deaths come a week after a deadly climbing season at Mount Everest where 11 people died after allegations of overcrowding on the world's highest peak.

Mountaineering experts criticised the government of Nepal for giving permits to anyone ready to pay $11,000, letting rookie climbers risk their lives and those of others on the slopes.