At least 25 people were killed by torrential rains that caused landslides and flooded Zhengzhou, a city in central China.
President Xi Jinping described the situation as "extremely serious" and flood control measures entered a "critical phase," state media reported on Wednesday.
Some 200.000 people were evacuated from Zhengzhou, local government officials said.
Soldiers lead rescue efforts in this city of more than 10 million people, where the equivalent of a year's average rain fell in just three days.
Rainfall in the region was the most intense since data began to be recorded 60 years ago.
According to scientists, climate change is worsening floods and other extreme weather events around the world.
The storms submerged the Zhengzhou subway late on Tuesday, causing 12 deaths and five injuries.
Images on social media showed shocked passengers battling rising waters inside a car. Rescuers opened the roof of the wagon to put people to safety, local media reported.
Other images showed rescues of pedestrians from the torrents running through the streets in Zhengzhou.
At least four people died in the nearby city of Gongyi, where houses and walls collapsed, according to the official Xinhua agency, which explained that the rains had caused multiple landslides.
Many outside of Zhengzhou sought information about their relatives on social media.
“I don't know more about your situation. I am in Tianjin and my parents are in Zhengzhou, ”said a user of the Weibo social network, contacted by AFP. "I am very concerned".
Priority for safety of life
Chinese President Xi Jinping on Wednesday called on authorities at all levels to give top priority to ensuring the safety of people's lives and property, and to carefully and strictly implement flood prevention and flood relief measures. disasters.
Xi, also general secretary of the Central Committee of the Communist Party of China and chairman of the Central Military Commission, made the remarks in an important instruction, after continued heavy rains hit regions such as Henan province, in the center of the country, causing large casualties, and loss of life and property.
The rain has made the flood control situation very severe, with severe waterlogging in Zhengzhou and other cities, water levels in some rivers exceeding alarm levels, and damage to dams in some reservoirs, Xi said. and added that sections of railways have also been closed and some flights have been canceled.
Xi stressed that authorities at all levels must always put people's safety and property first, and take the lead in fighting floods.
He ordered authorities at all levels to promptly organize flood prevention and disaster relief forces, adequately accommodate the victims, strictly prevent secondary disasters and minimize loss of life and property.
The People's Liberation Army and the Armed Police Force should actively assist local authorities in emergency relief and rescue work, Xi said.
The highest level of alert
Authorities decreed the highest alert level in Henan province as floods continue to hit the region, with landslides blocking many roads, evacuated villages, closed tourist spots and large isolated areas.
The cultural heritage body warned that some places had suffered water damage, including the Shaolin Temple - a famous monastery and martial arts school - and the Longmen Grottoes, a UNESCO heritage site with Buddhist carvings in stone dating back to the XNUMXth century.
Henan is the birthplace of traditional Chinese martial arts and is home to many kung fu academies.
The statement stated that "the main protected cultural relics suffered varying degrees of water damage," but stated that they were already safe.
The Chinese military said it had prevented the collapse of the Yihetan Dam, located an hour from Zhengzhou city.
On Wednesday the People's Liberation Army explained that blasting operations had been carried out at the dam and that troops had "successfully opened a new flood diversion opening."
These measures mean that the water level had dropped and that the "hazard has been effectively controlled."
Thousands of soldiers were deployed to other nearby rivers to reinforce the levees with sandbags as floodwaters swept through Henan and warnings of the danger were issued for other dams.
"Some reservoirs have seen their dams burst ... causing serious injuries, loss of life and material damage," Xi Jinping said, according to the state-run CCTV.
The floods of the annual rainy season in China wreak havoc, wiping out roads, crops and houses.
But the threat has worsened over the decades, due in part to the widespread construction of dams and levees that cut connections between the river and adjacent lakes.
With information from agencies