It was the first major avalanche on Mount Everest this climbing season, when hundreds of foreign and Nepali climbers flock to the mountain to attempt to climb its 8,850 meter (29,035 feet) peak.
The avalanche hit the sherpa guides between base camp and Camp 1 early on Friday, Pandey said.
Madhusudan Burlakoti, a senior official at the ministry, said helicopters and rescuers on foot had been sent to the site.
More than 4,000 climbers have scaled Everest's summit since it was first climbed by Sir Edmund Hillary and Tenzing Norgay Sherpa in 1953. Nearly 250 people have died on the mountain.
Nepal is home to eight of the world's 14 highest peaks.
Everest is on the border between Nepal and the Chinese region of Tibet and can be climbed from both sides.