Liberation Army troops carry food and other goods to local residents trapped in floods along the Huaihe River in Anhui, July 15, 2007.--Xinhua Photo

The Flood Control and Disaster Relief Headquarters of central China's Henan Province announced Sunday that it has opened a sluice twice this month to ease pressure on the swollen Huaihe River.

The sluice, located in Zhumadian City of Henan, was opened around 10:40 a.m. Sunday, discharging water from the Xiaohong River, a tributary on the upper reaches of the Huaihe River, to the Laowangpo buffer zone, an official with the headquarters said.

Heavy downpours since Friday have filled three major reservoirs along the tributary, lifting the water to a dangerously high level, the official said.

About 54,000 residents in the buffer zone were evacuated prior to July 6, when the sluice was opened for the first time this year.

The Laowangpo area covers 121.3 square kilometers and can store171 million cubic meters of water.

Chinese residents along the Huaihe River have been urged to gear up for their second tough combat against floods in a week as receding flood water on some branches of the river started rising again on Saturday after torrential rain.

When the last flood peak arrived, eight buffer zones along the Huaihe River were commandeered, including the Mengwa flood reservenear Fuyang in the eastern province of Anhui. The water discharge led to the evacuation of about 157,800 residents.

The Huaihe Flood Control Headquarters said the third flood peak will pass the Wangjiaba, a crucial hydrological station in Anhui Province, Monday afternoon, and they may have to discharge water from the station to Mengwa again if the water level climbs too high.

More than 30,000 People's Liberation Army troops have been helping with rescue efforts along the Huaihe River, which originates in Henan and runs east through Henan, Anhui and Jiangsu.

By Friday, a total of 403 Chinese had been killed as a result of flooding, 105 were missing and 3.17 million people had been relocated as the rainy season coupled with ferocious flood waters continues to batter central and southern China.