Blizzard conditions on Friday hit rescuers searching for 138 people buried by an avalanche at a high-altitude Pakistani army camp as more foreign teams were due in the country to help operations.

A huge wall of snow crashed into the remote Siachen Glacier base high in the mountains in disputed Kashmir early on Saturday morning, smothering an area of one square kilometre (a third of a square mile).

Low temperatures are hampering the effectiveness of heavy machinery being used to dig through the mass of snow and ice at the Gayari base, the military said on Friday.

Specialist high altitude teams from the United States, Germany and Switzerland are being sent by road and air to the remote site, the military said, while units from China and Norway are due to arrive in Islamabad soon.

Search teams are looking for the trapped soldiers and civilians at six different points on the site, around 4,000 metres (13,000 feet) up in the mountains.

Troops are attempting to dig a horizontal tunnel at the base of the main excavation site to reach what is thought to be one of the camp buildings.

More than 450 rescuers are working in sub-zero temperatures at the site, though experts have said there is virtually no chance of finding any survivors.

The site lies near the de facto border with India in the militarised region of Kashmir, which has caused two wars between the neighbours since independence in 1947.

The nuclear-armed rivals fought over Siachen in 1987, but guns on the glacier have largely fallen silent since a peace process began in 2004.