Authorities says mission to recover climbers' bodies likely to take 10 days.
Indian authorities will likely take around ten days to recover the bodies of five missing climbers believed to have been killed in an avalanche high in the Himalayas, government and police officials said.
The officials said authorities will conduct another aerial reconnaissance on Thursday or Friday to find a way to reach the bodies of the missing climbers or send a team on foot after the team has had time to acclimatise.
There is a possibility of another avalanche, making it a "very high-risk" operation, an official from the Indo-Tibetan Border Police told the media.
The recovery mission which included three helicopter sorties on Wednesday faced technical problems.
Dangerous rescue mission begins
An Indian helicopter carrying elite paramilitary mountaineers took off earlier on Wednesday to retrieve five dead climbers and three others believed killed scaling a treacherous Himalayan peak.
Air Force choppers spotted five bodies on Monday on the slopes of Nanda Devi in India's high north while looking for the four Britons, two Americans, one Indian and one Australian believed killed by an avalanche last week.
The remains of the three others, all part of originally a 12-member team led by highly experienced British climber Martin Moran, were believed to be nearby. Four other Britons split from the bigger group and were rescued on the weekend.
Wednesday's operation began at 2330 GMT (5:00 am local time) when a military helicopter with four Indo-Tibetan Border Police (ITBP) mountaineers and five Air Force personnel left the nearby hill town of Munsyari.
The ITBP climbers were to be dropped by the helicopter 5,500-6,100 metres (18,000-20,000 feet) up India's second-highest mountain, police spokesman Vivek Kumar Pandey told AFP.
Pandey on Tuesday described the mission as "a very high-risk and high-altitude operation" in a zone where avalanches are frequent.
"In recent times such a high-altitude retrieval has not been carried out in Indian mountains," he added.
Unauthorised route costs lives
The team led by Moran had permission to climb the eastern peak of Nanda Devi but a Facebook post by Moran's mountaineering firm on May 22 said that they planned to attempt "an unclimbed peak" around 6,500 metres (21,300 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 involved in the operation said on condition of anonymity on Tuesday.
"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.
Officials said the 12 climbers had set out from Munsyari but separated into two groups a week later.
The groups communicated last on May 26, a day before heavy snow fell and massive avalanches hit the heights.
When the eight climbers failed to report back to the base camp, the other four launched their own search before alerting Indian authorities who started a major search operation.
A military source said the climbers may have fallen from an ice ridge or an overhanging mass of snow during the avalanches.
"There must have been some error of judgement and they must have fallen from a great height along with the entire snow cornice. It must have been like falling from a 10-storey building," the source said.
"They took a different route for which they didn't have permission. It is their adventurism which cost them their lives," the source said.
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 among the toughest.
The other climbers have been named as John McLaren, Rupert Whewell and University of York lecturer Richard Payne from Britain, US nationals Anthony Sudekum and Ronald Beimel, Australian Ruth McCance and Indian guide Chetan Pandey.
McCance's husband Trent Goldsack told Australian media that her last communication to him had been a text message saying: "OK at base camp."