Image copyright AP Image caption Sherpa mountain guides have already held some talks with the Nepalese government

About half the teams at Everest base camp are descending amid uncertainty over this year's climbing season, after 16 guides were killed in an avalanche.

A row over local guides' share of revenue from foreign climbers erupted after last week's deadly accident, prompting some to threaten a boycott.

Sherpas also want better rescue and treatment facilities for guides.

If others descend, some fear it could effectively end plans to climb the world's highest mountain this year.

Ang Tshering Sherpa, the president of the Nepal Mountaineering Association (NMA), told BBC Nepali's Surendra Phuyal that was a distinct possibility if the majority of climbers decided to abandon climbing.

Media playback is unsupported on your device Media caption Jamling Tenzing Norgay tells 5 live: "Mountaineering is a teamwork"

But Madhusudan Burlakoti, a tourism ministry official, hoped that some teams might still climb. Sherpas have been in talks over these issues with the Nepalese government.

More than 300 foreigners were preparing to climb Everest this year, but the tense aftermath of the avalanche that killed 13 Sherpas and left 3 missing presumed dead dashed hopes and left many climbers disturbed and shocked, our correspondent reports.

Media playback is unsupported on your device Media caption This year's climbing season could be cancelled

About 50 expedition teams had been at the base camp, with 31 intended for Everest.

Some of the teams have chosen to go on trekking expeditions instead, while others are still waiting and watching, BBC Nepali's Navin Singh Khadka reports.

'Threats of physical harm' I was preparing for many months to climb Mount Everest, and that dream was coming true for me when I reached the base camp around the 17th. The avalanche happened the very next day. There was a mourning period for about four days, agreed between the Western expeditions and the sherpas. We stayed at base camp and some of our sherpas went back to their villages. They came back on the 22nd. The next day, after a religious ceremony to bless the expeditions, some of our sherpas as well as the sherpas of another bigger expedition received threats of physical harm and harm to their families. The people making the threats wanted to shut down the mountain. The day after, it was confirmed our expedition would not continue. As of [Friday], we understand that all the expeditions are shut down. Most of the climbers have left. There are media reports saying expeditions are leaving because it's not safe, but that's not true. Overall, the ice is not worse than the year before. We are terribly sad, especially for our sherpas. Some of them had lost brothers in the avalanche. The expedition team also made a lot of effort to prepare and now we are not summiting. It's like getting into a boxing ring, ready for the match after a year of preparation, and the match is suddenly cancelled. Why are climbers leaving Everest?

The government has assured teams that their climbing permits will remain valid for the next five years.

Last Friday's avalanche was the single deadliest accident in modern mountaineering on the world's highest peak.

It struck an area just above Everest base camp at 5,800m (19,000ft).

Greater risk

Sherpas can earn up to $8,000 (£4,800) in the three-month Everest climbing season - more than 10 times the average wage in Nepal, which remains one of Asia's poorest nations.

But BBC South Asia correspondent Andrew North says that does not look so good when the government is earning millions of dollars each year in fees for climbing permits. Some guiding companies charge up to $60,000 (£36,000) per person.

The guides who lost their lives had climbed up the slope early in the morning to fix ropes for climbers and prepare the route.

The avalanche struck a passage called the Khumbu Icefall, which is riddled with crevasses and ice boulders that can break free without warning.

Although relatively low on the mountain, it is one of its most dangerous points - but there are no safer paths along the famous South Col route first scaled by Sir Edmund Hillary and Tenzing Norgay in 1953.

Sherpas often make 20-25 round trips to carry kit and supplies to advanced camps, exposing themselves to greater risk.

Everest has been scaled by more than 3,000 climbers since 1953.