Paul Johnson reports from Controlling Water, where the water is out of control

In north-east China, Harbin city faced another deluge as the third flood crest in recent weeks swept down the Songhua river.

Hundreds of thousands of troops and civilians worked to protect embankments in the city and outlying areas.

Officials said they were confident the city's defences would hold, but there have been some leaks.

The president of China, Jiang Zemin, has postponed a trip to Russia and Japan because of the severity of the floods.

Shoring up the road between Harbin and Daqing

Large tracts of land on the edges of Harbin are under water and one of main bridges across the river has been closed.

Residents of a nearby island - normally a popular tourist resort - have been evacuated.

And state television has reported that troops have been called in to help re-open the city's flooded waterworks.

BBC's China Correspondent Duncan Hewitt reports from Harbin: "Wall of sandbags"

Downtown, defences have generally held, but there have been several leaks.

The waterfront Stalin Park has been closed after water seeped through a hastily-built wall of sandbags.

Further along the river, divers were called in to find the source of another leak.

Water levels have been 0.75m higher than in 1957, the year that held the record for the worst flooding.

Oil wells look all at sea

The immediate danger to China's biggest oilfields around Daqing, near Harbin, has receded, even though hundreds of wells remain under threat.

Throughout Harbin, people have been donating money to flood-relief efforts and a nationally-televised charity concert featuring pop stars and celebrities - some from Hong Kong and Taiwan - collected a reported $45m.

Elsewhere along the Songhua, battle is being lost.

As flood defences are strengthened in cities, villages are being surrendered to the waters.

Soldiers wade through flood waters

In Controlling Water village in the Northern Chinese province of Heilongjiang, the main street is awash after the river broke through a dike.

The devastation is just as widespread in central China where the Yangtze river has remained above emergency levels for more than a month.

But there was some relief in the city of Wuhan when a Yangtze flood crest passed without breaking through the dike defences.

Government figures say 2,000 people have died and millions have been left homeless.