By Jane Hughes
BBC correspondent at Everest base camp
A 25-year-old Nepalese Sherpa has set a new world record for the fastest ever ascent of Mount Everest.
Pemba Dorjie Sherpa went from base camp to the summit in 12 hours and 45 minutes.
Fellow climbers cheered the news of the record ascent
It takes most climbers a number of days to make the same journey.
The Everest base camp awoke early on Friday morning to the sound of loud cheers.
News broke that Pemba Dorjie Sherpa had become the fastest man ever to climb the world's highest mountain.
He left base camp late yesterday afternoon and climbed through the night under a clear and starlit sky and in temperatures well below freezing.
He reached the summit 12 hours and 45 minutes later, taking more than four hours off the previous record time which was also held by a Sherpa.
It takes most climbers four days of brutally hard climbing to make the same journey, but Pemba Dorjie Sherpa may not hold the new record for long.
There is another Sherpa here at base camp who claims he can go even faster.
Lakba Gelu says he will be making his own speed summit attempt within the next week and he hopes to achieve a time of less than 12 hours.
On Thursday a 70-year-old Japanese man became the oldest person to climb Mount Everest.
Yuichiro Miura made it to the top of the world's highest peak a week before the 50th anniversary of the first ascent.
Mr Miura, his son and seven others reached the summit via the south-east ridge route taken by Sir Edmund Hillary and Tenzing Norgay in 1953.