A dozen people died in a flooded subway line in Zhengzhou, the capital of China's central Henan province, after the city was drenched by what weather watchers said were the heaviest rains for 1,000 years.
Video posted on social media late on Tuesday showed commuters chest-deep in murky floodwaters on a train in the dark, and an underground station turned into a large, churning pool. More 500 people were pulled to safety from the subway flood, Zhengshou city authorities said.
Due to the rain, authorities in the city of 12 million people about 650 km southwest of Beijing, had halted bus services.
Amid torrential rains since last weekend, the death toll rose to at least 16 on Wednesday with four residents of Gongyi reported dead, according to local media. The city - located by the banks of the Yellow River, like Zhengzhou - has suffered widespread collapse of homes and structures due to the rains.
More rain is forecast across Henan for the next three days, and the People's Liberation Army has dispatched more than 3,000 soldiers and personnel to help with search and rescue.
From Saturday to Tuesday, 617.1 mm of rain fell in Zhengzhou. That's almost equal to Zhengzhou's annual average of 640.8 mm.
The rainfall in Zhengzhou over the three days was on a level seen only "once in a thousand years", local meteorologists said.
Like recent heatwaves in the United States and Canada and extreme flooding seen in western Europe, the rainfall in China was almost certainly linked to global warming, scientists told Reuters.
"The common thread here is clearly global warming," said Johnny Chan, a professor of atmospheric science at City University of Hong Kong.
"Such extreme weather events will likely become more frequent in the future. What is needed is for governments (city, provincial and national) to develop strategies to adapt to such changes."
'FLOOD PREVENTION DIFFICULT'
Across Henan, a major logistics hub with a population of around 100 million, many train services have been suspended. Highways have also been closed and flights delayed or cancelled.
A train from Zhengzhou had barely left city limits on Monday before it stopped, stranding hundreds of passengers. As of Wednesday, water and food supplies on the train have run out, according to local media.
Roads in a dozen Henan cities were severely flooded.
"Flood prevention efforts have become very difficult," President Xi Jinping said on Wednesday, addressing the situation in a statement broadcast by state television.
Dozens of reservoirs and dams also breached warning levels.
Local authorities said the rainfall had caused a 20-metre breach in the Yihetan dam in Luoyang city west of Zhengzhou, and that the dam "could collapse at any time".
In Zhengzhou, Guojiazui reservoir had been breached but there was no dam failure yet.
About 100,000 people in Zhengzhou have been evacuated.
A raft of Chinese companies, insurers and a state-backed bank said they had offered donations and emergency aid to local governments in Henan amounting to 1.935 billion yuan ($299 million).