Tourism in the vast, high-altitude area in China's western edge has increased in recent years, and outdoor enthusiasts flocked to its famous trekking spots for this year's eight-day national holiday that concludes Wednesday.

But an intense blizzard over the weekend buried camps and complicated travel, sparking a large-scale rescue operation involving firefighters, horses, yaks and drones.

In total, "580 hikers and more than 300 personnel, including local guides and yak herders, have arrived safely" in a nearby township, state news agency Xinhua reported Tuesday evening.

"Local staff are organising their return journeys in an orderly manner," the report said, adding that "about a dozen" additional hikers had been brought by rescue teams to a meeting point with supplies.

Their return to safety brings an end to rescue efforts in the mountainous Chinese region, though the unexpected extreme conditions have wrought further damage in nearby areas.

In the mountains of neighbouring Qinghai province, one hiker died from hypothermia and altitude sickness, state media reported Monday.

Over the border in Nepal and India, landslides and floods triggered by heavy downpours killed more than 70 people, officials said Monday, as rescue workers struggled to reach cut-off communities in remote mountainous terrain.