"Severe floods triggered by heavy rains will continue to threaten parts of southern China," Minister of Water Resources Chen Lei warned.
"There is an increasing possibility that downpours, with enhanced frequency and intensity, will continue to lash regions in the south," he said in a Sunday speech posted on his ministry's website.
Persistent heavy rains that began in the first week of June have swamped central and southern parts of China, with Chen saying more than 10 major rivers in affected areas were on the verge of bursting their banks.
The state weather bureau has forecast continued downpours over the next three days, and the summer typhoon season is approaching.
A recent three-hour downpour dumped a near-record of 312 millimetres of rain in Wangmo county in Guizhou province in the southwest, while over 200 millimetres of rain had fallen over short periods in numerous other regions, Chen added.
More than one million people in eight provinces, regions and municipalities were evacuated from their homes from June 9-16 due to flooding, according to the Beijing News.
More than six million people have been somehow "affected" by the rain and flooding in Hubei and Jiangxi provinces, while 2.65 million were affected in coastal Zhejiang province, it added.
The rains had left at least 168 people dead or missing as of last week, the Civil Affairs Ministry said at the time.
The rains have come as a jarring change for provinces including Hubei, Anhui, and Zhejiang, parts of which had until recently sweltered under the worst drought in decades.
Dykes stretching more than 70 kilometres along the Lan river in the city of Lanxi in Zhejiang province were at risk of bursting and authorities were preparing evacuation plans for local residents, Xinhua news agency said.
Heavy rains since Saturday caused the river's level to rise sharply, reaching its highest since 1966, it quoted a local official saying, with water already spilling over some sections.
In the south-western province of Yunnan, five people were killed and another was missing after surging floodwaters swept through a pair of rural villages during a hailstorm on Sunday, the agency said.
China is hit by heavy summer rainfalls every year.
Torrential downpours across large swathes of the country last year triggered the nation's worst floods in a decade, leaving more than 4,300 people dead or missing in floods, landslides and other rain-related disasters.
One devastating mudslide in the north-western province of Gansu killed 1,500 people last August.
Copyright AFP (Agence France-Presse), 2011