Kathmandu, May 22 -- What is the carrying capacity of Mount Everest? The question remains unresolved as Nepal once again witnessed massive overcrowding on the world's highest peak during the spring climbing season.

A drone video and photos that spread rapidly across social media this week showed a long, snakelike line of climbers moving between Camp III and Camp IV, highlighting congestion on Everest's narrow slopes. Expedition operators estimated that more than 300 people were on the route at one time.

On May 20 alone, more than 270 climbers reached the summit from Nepal's side, according to expedition agencies, reviving concerns over safety and regulation on the 8,848.86-metre mountain.

"We are yet to verify the numbers, but it's mos...