CNN  — 

China has indefinitely suspended all ultra-marathons and trail-running events in the wake of a mountain race that saw 21 runners die in extreme weather last month.

The staggering death toll of the 100-kilometer (62-mile) ultra-marathon in Gansu province triggered a public outcry over lax industry standards and weak government regulation.

On Wednesday, China’s General Administration of Sport said it is halting all high-risk sports events that lack a clear oversight body, established rules and safety standards, according to a statement on its website.

The sports suspended include mountain and desert trail running, wingsuit flying and ultra-long distance races, the statement said.

The administration did not specify how long the suspension would last, but said it is taking a detailed look into the country’s sports events to improve regulatory systems, strengthen standards and rules, and enhance safety.

It also ordered local authorities “not to hold any sports competitions unless necessary” and call off any event with safety risks in the lead-up to the Chinese Communist Party’s centenary, which falls on July 1.

Authorities didn’t say how many races will be affected by the suspension. According to the Chinese Athletic Association, 481 trail races and 25 ultra-marathons were held in 2019 – more than a quarter of all long-distance running events in the country.

Marathons and trail races have exploded in popularity as China’s rising middle class picked up the running bug in recent years. But industry insiders say the races are often poorly organized, lacking safety measures and contingency planning – and sometimes plagued by injuries and deaths.

Trail races are often held in far-flung parts of the country that lag behind in development and resources. The deadly mountain race on May 22 took place in the remote countryside of Gansu, one of the poorest regions in the country.

Most of the victims, including some of the country’s best long-distance runners, were poorly equipped for cold weather and died of hypothermia – a dangerous drop in body temperature caused by prolonged exposure to bitter cold.

The tragedy shocked China’s running community and prompted public outrage, with many questioning whether organizers had planned the race properly or prepared participants for the extreme weather.

Even before the announcement on Thursday, dozens of marathons and trail-running races had been canceled or postponed across the country in the past two weeks, according to state media.