Even as a Nepal tourism ministry official on Sunday declared a toll of 18 climbers on Mount Everest after Saturday's 7.9-magnitude earthquake, climbers in the area tweeted updates about the prevailing conditions around their respective base camps.

At 12.57 p.m., Jim Davidson, a climber at 19,850.03 feet, tweeted: "Just had our biggest aftershock yet here at C1 on Everest. Smaller than original quake but glacier shook & avalanches again. Nerve wracking...."

At around 1.30 p.m., Daniel Mazur, from Bristol, England, @danielmazur tweeted: "Aftershock @ 1pm! Horrible here in camp 1. Avalanches on 3 sides. C1 a tiny island. We worry about icefall team below... Alive?

Mazur, at around 11.00 a.m., in a tweet had said: "12+1 member #Everest BC TV team passed away. RIP. #Earthquake loosed tons of ice down, creating wind blast destroying BC' heart."

In the morning at 6.00 a.m., Adrian Ballinger, a climber from Squaw Valley, California wrote on Instagram: "Waking to clear skies, sun and a fresh coating of snow on #Everest. While our forecast predicts clouds will build quickly this afternoon, and more snow is on the way....

"I hope this window of clear allows for the most critically injured to be rescued from the South Side base camp by heli, and those less injured to begin descending under their own power.

"Good weather should also allow climbers and Sherpas to continue their search in the debris for victims. We are holding a puja with our Sherpa, and beginning to consider what happens next. #everest2015 #earthquake," Ballinger posted.

At about noon, mountaineer Alex Gavan, @AlexGAVAN tweeted: "Just another earthquaqe now. And another three small avalanches. All good. Pfiu!!!

Around 1.00 p.m., Ballinger tweeted: "Another big one. Really big. Rockfall off surrounding peaks in North Side #everest base camp. Worst possible news for south. #earthquake"