China, already hit by torrential downpours that have left more than 260 dead or missing, braced Tuesday for more rains and wind as a tropical storm neared its southern coast, weather authorities said.

The state weather bureau said the storm was brewing at sea off the coast of Guangdong and Fujian provinces, and was likely to bring strong winds and heavy rain to the region over the next two days.

Summer downpours have pummelled large swathes of south and central China this month, triggering deadly floods and landslides that have forced authorities to evacuate more than 1.6 million people.

The rains have left at least 261 people dead or missing while more than 36 million have been "affected" one way or another by the rain and flooding, the civil affairs ministry said Monday.

But the state flood headquarters sounded a positive note Tuesday, saying the downpours in flood-hit areas were receding.

In the populous eastern province of Zhejiang, where nearly 300,000 people had been evacuated along the Qiantang river as the waterway threatened to burst its banks and flood towns and villages, the water fell below warning levels.

The National Meteorological Centre on Tuesday forecast intermittent showers and thunderstorms in parts of the hard-hit flooded regions over the next three days, but said heavy rains in south and central China were unlikely.

China is hit by torrential summer rainfalls every year.

Heavy downpours across large swathes of the country last year triggered the nation's worst flooding 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 northwestern province of Gansu killed 1,500 people last August.