UPDATE 10pm 26/02/2018: Desnivel.com have been in contact with the team. Urubko has descended to Base Camp and has withdrawn from the expedition. The team released the following statement: "Denis Urubko, following his beliefs about the end of the winter season, decided to abandon the winter expedition on K2. This decision was accepted by the participants in the expedition who did not see more opportunities to cooperate with Denis after his attempt to reach the summit."
Drama unfolded on K2 (8611m) on the China-Pakistan border over the weekend as Russian-Polish mountaineer Denis Urubko abandoned his team attempting the first winter ascent of the mountain and set off alone following an argument. Urubko reportedly told expedition leader Krzysztof Wielicki that he wanted to summit two weeks earlier than planned, in order to log an official winter first ascent. 28th February is considered the meteorological end of the winter season, while some mountaineers consider 20th March - the astronomical end of winter - to be the cut-off date.
Having established a new route on the Abruzzi ridge, Urubko and Adam Bielecki - the team's two strongest climbers - spent one night acclimatising at Camp 3, whilst other members of the team arrived at Camp 1. On Friday evening, Urubko proposed an early summit attempt to Adam Bielecki, who refused due to the his and the team's unreadiness to push for the summit so soon.
Urubko responded with anger and stormed out of the tent. The following morning he set off alone up the mountain, without a radio to allow contact with his team.
"He has had a heated debate with the team leader and left for the summit without saying a word," a porter with the group told AFP news agency.
Speaking to Mark Jenkins for a National Geographic report by sat phone, Wielicki commented: "What Denis has done is very selfish. Denis thinks it's all about just him, but it's not. He has put all of us in danger. If something goes wrong, of course we must try to rescue him."
Wielecki has sent climbers to follow Urubko and has vowed to support him in a safe return from the mountain.
"We must now focus the whole team on helping Denis," Wielicki told National Geographic. "No matter what happens on the summit we want him to get back down alive." As of Sunday morning, the team were unsure of Urubko's location.
Last month, Urubko and Bielecki were involved in the dramatic rescue of French mountaineer Elisabeth Revol on Nanga Parbat in Pakistan.
Despite being the world's second-highest mountain, K2 has a higher fatality-to-summit rate than Everest due to its extreme steepness and weather conditions.