Xi orders 'all-out' rescue as floods kill 10 in northwest China

President Xi Jinping on Friday ordered "all-out" rescue efforts in China's arid and mountainous northwest after flash floods caused by exceptionally heavy rain killed 10 people and left 33 missing.

Torrential downpours began around 6 pm on Thursday and unleashed flash floods in Gansu province's Yuzhong, stranding some 4,000 people, state broadcaster China Central Television (CCTV) reported.

In one mountainous area, precipitation had reached up to 195mm since early Thursday evening. Yuzhong county normally sees 300-400mm of rainfall for the entire year.

Yuzhong is situated among gullies and hills of wind-blown silt on one of the world's biggest loess plateaus. That makes it vulnerable to flash floods and landslides given the loose structure of the soil, which becomes unstable when saturated with water.

Ankle-high muddy water could be seen coursing down a hilly road flanked by uprooted trees in a video posted by CCTV.

"The top priority must be to make every possible effort to search for and rescue missing people, relocate and resettle people under threat, minimise casualties, and restore communications and transportation as quickly as possible," CCTV quoted Xi as saying.

He warned local governments not to succumb to "complacency and carelessness" in light of recent occurrences of extreme weather, CCTV said.

Record rainfall has lashed China's north and south in recent weeks in what meteorologists describe as extreme weather events linked to climate change.

Heavy rains and flooding have killed at least 60 people across northern China including Beijing since late July.

The National Development and Reform Commission said on Friday it has allocated 100 million yuan ($13.92 million) to support rescue efforts in Gansu following the disaster.

China has announced at least 6 billion yuan of funding for disaster relief since April.