Pakistani rescuers were searching on Wednesday for a Spanish man and an Argentinian who went missing on a notoriously treacherous Himalayan peak known as "Killer Mountain", an official said.

A ground team began searching for Alberto Zerain Berasatei from Spain and Mariano Galacan from Argentina but helicopters could not join the search effort due to poor weather, said Karrar Haidri, spokesman for the Alpine Club of Pakistan.

The two men, who were part of a 13-strong expedition that set out last month to climb the 8,126-metre Nanga Parbat , the world's ninth highest mountain, were last heard from on Saturday.

The rest of their party had returned to base camp, Haidri confirmed.

"In such weather conditions and without adequate food supply, survival appears unlikely but there was the case of Tomaz Humar a few years ago," Haidari said, adding that rescue officials are doing everything possible to find the men.

Slovenian mountaineer Humar was trapped on Nanga Parbat for six days in 2005 before Army helicopters found him trapped under a ledge at a height of nearly 6,000 metres.

Pakistan rivals Nepal for the number of peaks over 7,000 metres (23,000 feet) and is home to the world's second-highest mountain, K2, as well as three others which are among the world's 14 summits higher than 8,000 metres.

In 2013, gunmen dressed as police officers shot 10 foreign mountaineers and a local guide at Nanga Parbat 's 4,200-metre base camp.

The attack, later claimed by the Taliban, resulted in a major decrease in climbing expeditions, wrecking communities dependent on climbing tourism for income and depriving Pakistan's economy of much-needed dollars.