About 343,900 of the 488,800 relocated people came from Anhui Province and the rest from the provinces of Henan and Jiangsu.

The three provincial authorities have mobilized 511,000 people to patrol the Huaihe embankments and issue emergency warnings, according to information from the State Flood Control and Drought Relief Headquarters.

Thirteen sluices at Wangjiaba, a key hydrological station on the river after it flows out of central China's Henan Province and enters Anhui, were opened to divert waters to adjacent Mengwa buffer zone, home to 150,000 people.

The move should bring relief to more than 2 million flood-hit residents in Henan Province, on the upper reaches of the Huaihe River, and alleviate pressure downstream, said Qiu Ruitian, deputy director of the Office of the State Flood Control and Drought Relief Headquarters.

However, At 4:00 a.m. Wednesday, the water level at Wangjiaba was 29.59 meters and it fell slightly to 29.55 meters later in the day, according to Huaihe River Flood Control and Drought Relief Headquarters.

The pressure on the embankments along both banks of the Huaihe River has been mounting, endangering the safety of key cities and railway lines on the middle and lower reaches of the river.

The Anhui Provincial Flood Control and Drought Relief Headquarters was forced to put into use three minor flood diversion zones downstream of Wangjiaba on Wednesday morning and to open 14 sluices at Jiangtanghu to divert water on Wednesday afternoon.

Cui Li, deputy head of Yingshang County Flood Control Headquarters, said 43 households, 132 people in all who had been living in low-lying areas of Jiangtanghu, had relocated by 10:00 a.m. on Tuesday.

"Eighty police were mobilized to help residents remove their belongings and thorough searches were also made to ensure all residents in dangerous areas were moved to higher ground," said Cui.

Anhui flood control workers have been racing to open the embankment at the unpopulated Qiujiahu so that floodwaters could be diverted there.

The Huaihe River originates from Mount. Taibai, Henan Province, and runs eastward between the Yellow River and the Yangtze River, cutting through Henan and east China's Anhui and Jiangsu provinces before entering the Yangtze River via the Hongze Lake.

Tuesday's opening of 13 sluices could damage up to 12,000 hectares of cropland inside the 180-square-kilometer Mengwa flood storage area. The impact on the residents was expected to be limited, said local authorities.

Created in 1953, the area contains four townships, where most of the residents live in homes built more than 31 meters above sea level.

To prepare for Tuesday's diversion, four new protective structures have been built around existing embankments to accommodate 3,684 people who used to live in Mengwa's low-lying areas.

Meanwhile, the level of Hongze Lake on the lower reaches of the Huaihe River rose to 13.79 meters by 8:00 a.m. on Tuesday, 0.29 meters above the danger line, and is still rising.

Flood control workers at Tuesday noon opened more sluices on the lake to discharge water into the Yihe River and an irrigation canal running to the sea. Last week, they opened another sluice to allow floodwaters to flow into the Yangtze River, the country's longest.

Continuous torrential rain since late June has caused widespread flooding across China, especially in southern areas, including the Huaihe River valley, the provinces of Sichuan, Hubei, Shaanxi, Henan, Anhui and Jiangsu, and Chongqing Municipality.

The death toll in the seven flood-hit provinces had risen to 131 and another 31 are missing, the Ministry of Civil Affairs reported on Tuesday.

Nationwide, more than 66.3 million Chinese have been affected by floods this summer, with 360 people killed and losses amounting to 24.3 billion yuan, the State Flood Control and Drought Relief Headquarters announced on Wednesday.

China's central government set aside 232 million yuan (about 31.35 million U.S. dollars) on Wednesday to finance the ongoing battle against floods in Anhui, Jiangsu, Henan, Hubei and Sichuan provinces.

Also Wednesday, Chinese President Hu Jintao and Premier Wen Jiabao urged local governments to try to improve weather monitoring, give priority to people's safety and properly relocate people in flood-hit areas.

Several working teams have been dispatched by the central government to flood-stricken areas to guide disaster relief work. One of the working teams, headed by civil affairs minister Li Xueju, arrived in Anhui on Wednesday. Another team, headed by executive deputy minister of civil affairs, Li Liguo, arrived in Sichuan on Tuesday.