File photo of Mount Qomolangma. An avalanche swept down a slope of Mount Qomolangma on April 18, 2014, killing 12 Nepali mountaineering guides at the beginning of the main climbing season, a Tourism Ministry official said. [Photo/icpress.cn]

KATHMANDU - The death toll from an avalanche on Mount Everest in Nepal rose to 13 and most of them were local Sherpa guides making technical preparations for climbing season beginning next week, officials confirmed Friday.

An avalanche hit Khubuche area near Camp 1 of Mount Everest at around 5:30 a.m. local time.

"The bodies of the deceased have been brought down to the Everest base camp by chopper," Lamakaji Sherpa, chief of Sagarmatha Pollution Control Committee (SPCC) told Xinhua by phone.

Eight have been rescued and brought to the base camp for treatment while the Tourism Ministry has already sent three choppers to the site to support the rescue operation.

As more than ten people remained missing, the authorities fear the death toll might rise. So far, none of the foreigners have been reported dead.

The search and rescue operation has been hampered due to bad weather conditions.