Hundreds of sections of embankments along China's third-longest river have become loose after three weeks of deadly floods across the country.
Torrential rain has wrought havoc across large parts of China this summer, killing more than 500 people and causing billions of dollars in damage.
The swollen Huai River has displaced about half a million residents people since the start of this month in the central province of Henan and the eastern provinces of Anhui and Jiangsu, and many people are unable to return home.
Tens of thousands of troops were on guard to battle any breaches along the Anhui section of the Huai, which has reported 546 places of "danger", including 46 serious ones, Xinhua news agency said.
Dozens of villages were deliberately inundated in Anhui to ease pressure at the height of the flood, which Xinhua said was "moderating". That could change with more rain forecast today in the upper reaches of the Huai.
In southwestern Chongqing, residents were coping with the aftermath of the worst rainstorm in more than a century. At least 42 died in floods, landslides and other disasters.
Tens of thousands of rural residents whose houses were destroyed were living in schools and tents and depended on rations, Xinhua said, adding downpours were expected to batter Chongqing and neighbouring Sichuan province again today.