In this photograph taken on August 7, 2014 a sign points towards a view of Nanga Parbat (background), the killer mountain on Karakoram Highway in Pakistan's nothern area of Gilgit.
CNN  — 

Rescuers are searching for two mountain climbers missing on a peak in Pakistan, including a British man whose mother died in the same region in 1995.

Mountaineers Tom Ballard and Daniele Nardi have been missing for over a week, after contact was lost with them during an ascent of Nanga Parbat, in the Himalayas.

According to a statement published on Nardi’s Facebook page, “traces of (an) avalanche” were seen by rescuers near the pair’s base camp during a helicopter flyover last week.

Another post on the page, which is being updated by colleagues of Nardi’s, said a team of four mountaineers landed in the area Monday, and began searching it on foot and using drones, “but no traces of Daniele and Tom were found.”

Italy’s Ambassador to Pakistan, Stefano Pontecorvo, said on Twitter that efforts had resumed Tuesday. “Plan is to reach Camp 3 and search the surroundings also with the help of the drones.”

While the pair have not been heard from for over a week, both Nardi and Ballard are highly experienced mountain climbers, and are skilled at navigating hostile conditions with limited oxygen.

On GoFundMe, an appeal started by supporters has raised almost $150,000 to assist the rescue effort.

“The helicopter rescue operation costs roughly €50,000 per day,” organizers wrote on the fundraising website. “Donations to help support these costs are graciously appreciated. Any unused donations will be donated to the schools of Pakistan where Daniele has regularly donated school materials and medicine on this and past expeditions.”

Adding to the potential tragedy, according to the BBC, Ballard is the son of British climber Alison Hargreaves, the first woman to conquer Everest unaided in 1995. Hargreaves died that same year during a descent of K2.

The ninth-highest mountain in the world, at 8,215 meters (26,658 feet), Nanga Parbat is known as the “killer mountain” for the high number of fatalities suffered by those who attempt to summit it.