ISLAMABAD (AFP) - Two New Zealand climbers have gone missing after an avalanche on the world's second-highest mountain, K2, a Pakistani official said on Monday.

Mr Martin Walter Schmidt, 53, and his 25-year old son Denali Walter Schmidt went missing at Camp 3 on the 8,611-metre mountain on Saturday, said Mr Manzoor Hussain, chief of the Alpine Club of Pakistan that coordinated the expedition.

Two Nepalese Sherpas had gone up and reported that Camp 3 was damaged by an avalanche and both men were missing, he told AFP.

In recent days, several avalanches on the mountain had forced all climbers to return to base camp. The New Zealanders were waiting at Camp 3 for the weather to clear, he said.

A separate rescue has been called off for three Spanish climbers who went missing in bad weather after scaling the 8,068-metre Gasherbrum-I peak in the Karakoram range on July 21, he added.

In addition, three Iranian climbers who went missing on July 16 on another mountain are presumed dead, according to officials.

Pakistan is home to five of the world's 14 peaks over 8,000 metres. Deaths among climbers are not uncommon.