KATHMANDU, Nepal - Search teams recovered a 13th body Saturday from the snow and ice covering a dangerous climbing pass on Mount Everest, where an avalanche a day earlier had swept over a group of Sherpa guides in the deadliest disaster on the world's highest peak.

Three guides remained missing, and searchers were working quickly to find them in case the weather deteriorated, said Maddhu Sunan Burlakoti, head of the Nepalese government's mountaineering department. But the painstaking effort involved testing the strength of newly fallen snow and using extra clamps, ropes, and aluminum ladders to navigate the treacherous Khumbu icefall, a maze of immense ice chunks and crevasses.

The avalanche slammed into the guides about 6:30 a.m. Friday near the "popcorn field," a section of the Khumbu known for its bulging chunks of ice. The group of about Sherpa guides were among the first people making their way up the mountain this climbing season. They were hauling gear to the higher camps that their foreign clients would use in attempting to reach the summit next month.

One of the survivors told his relatives that the path had been unstable just before the snow slide hit at an elevation near 19,000 feet. The area is considered particularly dangerous because of its steep slope and deep crevasses that cut through the snow and ice covering the pass year round.

As soon as the avalanche occurred, rescuers, guides, and climbers rushed to help, and all other climbing was suspended.

Seven of the 12 bodies pulled out and brought down Friday were handed over to their families in the Everest region, and the remaining five were taken to Kathmandu, Nepal's capital.

Four survivors were conscious and being treated in the intensive care units of several Kathmandu hospitals for broken ribs, fractured limbs, punctured lungs, and skin abrasions, according to Dr. C.R. Pandey, of Grande Hospital. Others were treated for less serious injuries at the Everest base camp.

Hundreds of climbers, guides, and support-crew members were at Everest's base camp preparing to climb the 29,035-foot peak when weather conditions are most favorable next month.