The avalanche hit a battalion headquarters in the glacier's Gayari sector at 5.45am on Saturday, according to Abbas.
He told the BBC: "Some bodies have been recovered but it's too early to say how many have survived and how many bodies have been recovered."
He said people were praying the rescue operation would be successful and that it was extremely rare for an avalanche to reach the army base.
Siachen is on the northern tip of the divided Kashmir region claimed by both India and Pakistan. Both countries station thousands of troops there, who brave cold temperatures, altitude sickness and high winds for months at a time. Troops have been deployed at elevations of up to 6,700 meters (22,000 feet) and have fought intermittently since 1984, though the area has been quiet since a ceasefire in 2003. The glacier is known as the world's highest battlefield.
The headquarters in Gayari are the main gateway through which troops and supplies pass on their way to more remote outposts in the sector. It is situated in a valley between two high mountains, close to a military hospital, according to an officer who was stationed there in 2003.
"I can't comprehend how an avalanche can reach that place," said the officer. "It was supposed to be safe."
More soldiers have died from the harsh weather than combat on the glacier, which was uninhabited before troops moved there.
Conflict began there in 1984 when India occupied the heights of the 49-mile-long glacier, fearing Pakistan wanted to claim the territory. Pakistan then deployed its troops and both armies remain entrenched despite the ceasefire, costing the poverty-stricken countries millions of pounds each year.
Pakistan and India have fought three wars since the partition of the subcontinent on independence from Britain in 1947. Two of the wars have been over Kashmir, which both claim in its entirety.
Intellpuke: You can read this article by Guardian Reporter Damien Pearse, with reporting by various news agencies, in context here: www.guardian.co.uk/world/2012/apr/07/pakistan-avalanche-rescuers-search-soldiers