Climbers on Mount Everest are on the brink of the first attempts in three years to make the final ascent to the world's tallest peak, after fatal avalanches cut short the 2014 and 2015 campaigns.
Teams at forward camps are looking for a weather "window" to open in the next few days, clearing the way to the 8,850 meter (29,035 foot summit) along the Southeast Ridge first climbed by New Zealand's Sir Edmund Hillary and Sherpa Tenzing Norgay in 1953.
The southern route, on the Nepali side of the mountain, has suffered tragedy over the past two years, with 16 sherpa guides killed by an avalanche in the treacherous Khumbu Icefall in 2014.
Last year, an earthquake that killed 9,000 people across Nepal sent a massive snowslide crashing into Base Camp, killing at least 18 climbers and guides and putting an end to that year's campaign.
At least 289 climbers and their guides are in different high camps waiting for a weather window and jostling to become the first to scale the peak. Nearly 700 people summited in 2013.
Tourism Department official Gyanendra Shrestha said climbers had fixed ropes up to the South Col, the final camp, at about 8,000 meters (26,246 feet), and were stocking it with supplies.
"Climbers have begun to move from the base camp to higher camps for the summit," Shrestha told Reuters from Base Camp.
Ang Tshering Sherpa, chief of the Nepal Mountaineering Association, who is in touch with climbers at Base Camp, said in Kathmandu that, weather permitting, the route from the South Col to the summit would be fixed on Wednesday.
"Climbers will then start making summit attempts from Thursday," Sherpa told Reuters.
Veteran mountaineer and blogger Alan Arnette, tracking the campaign, said in a post eight teams had slept at Camp 3 - at 7,162 meters (23,497 feet).
Unpredictable weather remains a challenge though this year's campaign has been free of incident.
Climbers from around the world spend tens of thousands of dollars to try to climb Everest every year though none reached the summit in last year's spring campaign.
Last September, Japan's Nobukazu Kuriki, 33, had to call off his solo attempt when he was beaten back by wind and snow at 8,150 meters (26,738 feet).
Wang Jing, a 40-year-old Chinese woman, was the only person to climb Everest in 2014 but her ascent sparked controversy amid reports she took a helicopter over the Khumbu Icefall, in what many Everest climbers saw as a violation of their code.