A high-level Nepalese panel made of up government officials, climbing experts and agencies has issued a recommendation that all climbers seeking a permit for Mount Everest must have prior high altitude mountaineering experience and demonstrable training, The Guardian reported.

The panel was charged with looking at the issue of high-altitude safety after one of the deadliest seasons in recent years on Everest, which was blamed on inexperience and crowding near the summit.

Eleven climbers were killed or went missing on the 8,850-metre (29,035 ft) mountain in May, nine on the Nepalese side and two on the Tibetan side. Some say the carnage could have even been worse, if not for the heroics of some climbers and guides.

Some veteran guiding companies had long warned of the dangerous consequences of inexperience and crowds on the summit slopes, criticizing officials for allowing anyone who paid  US$11,000 free access to the word’s tallest mountain, regardless of their alpine expertise.

“Climbers to [Everest] and other 8,000-metre mountains must undergo basic and high altitude climbing training,” the panel said in the report it submitted to the government.

It said that those hoping to climb Everest must have climbed at least one Nepalese peak of more than 6,500-metres (21,325 ft) before getting a permit. Climbers must also submit a certificate of good health and physical fitness and be accompanied by a trained Nepalese guide.

Mira Acharya, a member of the panel, said: “Climbers died due to altitude sickness, heart attack, exhaustion or weaknesses, and not due to traffic jams.”

She said the compulsory provision of guides for each climber was to discourage solo attempts, which put lives at risk.

Nepal is home to eight of the world’s 14 highest mountains,  and mountain climbing is a key source of employment and income for the poor nation.

The numbers attempting the climb in May led to bottlenecks in the “death zone,” where very low oxygen levels put lives at risk. Oxygen cylinders ran out while as many as 100 people waited in the queue, the report said.

The issues were underlined by Simon Lowe, the managing director of UK-based Jagged Globe, who said this year’s crowding had aggravated an underlying issue of lack of experience.

“That is incompetent climbers being led by incompetent teams,” Lowe said. “If you go up with a bare minimum bottles of supplementary oxygen and stand in a queue for ages that is going to cause problems.”

Without reforms such as those suggested by the panel, Lowe said guiding on the mountain by responsible companies could become untenable.

Nepal issued 381 permits for Everest for this year’s climbing season, which tends to culminate in May, when the daylight and weather are the most forgiving.

Ghanshyam Upadhyaya, a senior tourism ministry official, said the recommendations would be implemented.