Large swaths of China's central Henan province are flooded, with Zhengzhou, the province's capital, being the hardest hit after being drenched by the highest rain in 1000 years, according to weather forecasters.

According to the official Xinhua news agency, 12 people have died so far in the floods in Zhengzhou, a city of more than 12 million people on the banks of the Yellow River, and around 100,000 people have been evacuated to safe zones, according to the local authorities.

Millions of people's lives have been turned upside down in Henan since the weekend due to an exceptionally active rainy season that has resulted in the quick rising of a number of rivers in the large Yellow River basin.

Many train services have been halted in Henan, a major logistics hub in central China. Many roadways have been closed, and flights have been rescheduled or canceled.

A dozen major cities' roads have been flooded. Residents were seen wading through streets amid fast-moving water in videos posted on social media. An adult and a child have washed away on a major artery jammed with half-submerged automobiles, according to one video.

Zhengzhou had 617.1 mm of rain from Saturday night to late Tuesday, virtually matching the city's annual average of 640.8 millimeters.

The amount of rain that fell in Zhengzhou over the course of three days was "once in a thousand years," according to meteorologists quoted by local media.

On Tuesday, a dramatic video posted on social media showed people knee-deep in murky floodwaters on a lightless subway train and an underground station transformed into a vast, churning pool.

Hundreds of reservoirs and dams have also exceeded their safety limits.

Local officials stated overnight that heavy rains had caused a 20-meter breach in the Yihetan dam in Luoyang, west of Zhengzhou, and that the dam "could collapse at any time."

The Guojiazui reservoir in Zhengzhou has been breached, according to the local flood control headquarters.

According to official media, Zhengzhou's transportation system remained paralyzed on Wednesday, with schools and hospitals cut off due to severe flooding.

Since Tuesday, several youngsters have been locked in their kindergartens.

The People's Daily reported on Wednesday that the First Affiliated Hospital of Zhengzhou - a huge treatment center with more than 7000 beds – had lost all power and that backup supplies were also down.

According to the story, the hospital was scrambling to obtain transportation for roughly 600 severely ill patients.

Heavy rain is expected to continue through Wednesday, with precipitation expected to continue for the next three days across the province.