At least 10 people died and 33 were missing after a flash flood struck Yuzong county in China’s Gansu province on Friday.
The flood was triggered by torrential rain, which has been battering the northwestern province since Thursday evening, and left around 4,000 people stranded, state broadcaster CCTV reported.
The heavy rain also caused a landslide in the mountainous Maliantan village near Lanzhou city, leaving three people missing late on Thursday.
Authorities said Lanzhou had received 195mm of rain by early Friday.
Yuzhong county typically gets 300-400mm of rain over an entire year.
A video posted by CCTV showed ankle-high muddy water coursing down a hilly road flanked by uprooted trees.
The torrential downpour also caused an outage of power and telecommunication services in the Xinglong mountain area, affecting more than 4,000 people in four villages.
Chinese president Xi Jinping ordered an “all-out” rescue effort in the arid northwest region after the flash flood.
"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," he was quoted as saying by CCTV.
The president warned local governments not to succumb to "complacency and carelessness" in the face of extreme weather events.
Yuzhong occupies gullies and hills of wind-blown silt on one of the planet’s largest loess plateaus. The loose soil, which becomes unstable when saturated with water, makes the area vulnerable to landslides and flash floods.
In the wake of the disaster, the National Development and Reform Commission said it had allocated 100 million yuan (£10.3m) to support rescue work in Gansu.
The central administration has announced at least 6 billion yuan of funding for disaster relief since April.
China has been receiving record rainfall in recent weeks. The rainfall and flooding have killed at least 60 people in the north, including Beijing, since late July alone.
