Pakistani troops began excavating a new site in their search for 138 people buried by an avalanche at a high-altitude army camp despite a fresh slide in the area, the military said on Saturday.

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

A fresh slide at the same site created difficulties for troops conducting search operations in low temperatures, intermittent snowfall and blizzards, the military said in a statement, without specifying the date of the new slide.

"The rescuers have commenced excavation at a new site, using plant equipment and infantry troops," it said.

"The search teams conducted first level explosion to dig further into hard mass of snow against the tunnel being attempted to access a suspected structure at an important excavation site".

Specialist high altitude teams from the United States, Germany and Switzerland are being sent by road and air to the remote site 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 were also 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.