Bad weather on Monday hampered efforts to boost the search for 135 people buried in an avalanche at a Pakistani army camp, as a US team of high altitude specialists arrived in the country to help.

It has been over two days since a huge wall of snow crashed into the remote Siachen Glacier base high in the mountains of Kashmir, and experts say there is little hope of finding survivors, though no bodies have been recovered yet.

Specially trained search-and-rescue teams of army engineers equipped with locating gadgets and heavy machinery on Sunday joined rescue units aided by sniffer dogs and helicopters.

But a senior military official said attempts to send extra equipment up to help with the search on Monday had been delayed.

"We had planned to transport some heavy machinery from Rawalpindi to Siachen but could not do so because of bad weather," the official told AFP on condition of anonymity.

"We had arranged a C-130 cargo plane to lift some machinery up to the area, but bad weather did not allow the flight."

The camp was engulfed between 5:00 am and 6:00 am on Saturday by a mass of snow, stones, mud and slush more than 1,000 metres (3,300 feet) wide and 25 metres high, according to the military.

An eight-member American team of high altitude search and rescue specialists arrived in Pakistan late on Sunday to help with the search effort, the US embassy said.

A Pakistani security official involved in the work told AFP the US team was expected to reach the site later on Monday, adding that operations were likely to go on for some time.

"It was a massive snow slide and looks like the rescue work will take days," the official said.

The US assistance comes as Washington and Islamabad try to patch up their relationship, badly damaged last year by the discovery of Al-Qaeda leader Osama bin Laden in Pakistan and US air strikes that killed 24 Pakistani soldiers.

Two expert teams from Switzerland and Germany were also due in Islamabad on Monday to assist the rescue operation, the military said in a statement.

Pakistan's powerful army chief General Ashfaq Kayani on Sunday visited the site in the militarised region of Kashmir, which has caused two of the three wars between India and Pakistan since their independence in 1947.

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

India and Pakistan have spent heavily to keep a military presence in the frozen area, where temperatures can plunge to minus 70 degrees Celsius (minus 95F).