Twenty-one people died after extreme cold weather struck a mountain track where they were taking part in a 100km ultra-marathon in China.

The runners were three hours into the race when they encountered hail, freezing rain and  gale-force winds  about midday on Saturday.

“A few people have already lost consciousness and are foaming at the mouth,” wrote an unidentified participant in the runners’ WeChat group, which was published in local media. “Come and save us, quick!”

A rescue operation involving more than 700 personnel extended through the night. Authorities confirmed yesterday that 21 of 172 participants in the high-altitude race had perished, making it one of the deadliest incidents in China’s sporting history.

The victims included two of China’s professional long-distance runners, Liang Jing and Huang Guanjun, according to local media reports.

The race was backed by the Baiyin city government, which covers the mountainous race area in north-western Gansu province, and the Chinese Athletic Association.

The runners were racing on an extremely narrow mountain path at an altitude reaching 2,000-3,000 metres

The race also followed a relatively established course, having been held four times, according to an account posted online by a participant who quit and managed to make his way to safety. 

But the weather caught them off guard, and on the morning of the race , he already sensed things were not normal. The runners were not dressed for winter-like conditions, with many wearing short-sleeved tops.

Some runners farther along the course had fallen off the trail into deep mountain crevices, according to state broadcaster CCTV. It was not clear how many of them survived.

On social media, people  expressed incredulity that organisers were not better prepared for the race. 

“Didn’t anyone look at the weather forecast?” asked one person on the Twitter-like Sina Weibo. “They were treating human lives as a joke.”

The mayor of Baiyin, Zhang Xuchen, expressed guilt and remorse. He and other officials stood up and bowed their heads at a press conference. “As the event’s organiser, we feel a deep sense of guilt and self-blame, express our deep mourning for the victims and deep condolences to their families and the injured runners,” he said.

The race began at 9am on Saturday in the Yellow River Stone Forest. Three hours later, a section of the rugged course –  between kilometre 19 and 30 – was “suddenly affected by disastrous weather”, the mayor said.

After receiving messages for help from some runners, race organisers sent a rescue team that managed to save 18 people. By 2pm, weather conditions had worsened and the race was stopped.

One survivor said: “My whole body was soaked through, including my shoes and socks. I couldn’t stand up straight because of the wind. I was very worried I’d be blown over.”

The province’s weather bureau had warned on Friday of adverse conditions including “sudden heavy showers, hail, lightning, [and] sudden gale-force winds”.

Liang Jing had won several Chinese ultra-marathons in recent years, and Huang Guanjun won the men’s hearing-­impaired marathon at China’s National Paralympics Games in 2019.