Water levels on many rivers, including the mighty Yangtze, have been unusually high this year because of torrential rains.

Three floodgates of the Three Gorges Dam that spans the Yangtze were opened as the water level behind the massive dam rose more than 15 metres above flood level, the official Xinhua News Agency reported.

State media reports showed rescuers wading in waist-high waters to evacuate people from their homes.

Torrential rain that have swept through China have killed at least 154 people and left 124 missing, officials said Saturday, with most of the casualties reported from a northern province where villagers complained about lack of warning before a deadly flash flood.

A flash flood has struck a scenic area outside the city of Xi'an in central China, sweeping away nine Chinese tourists, state media reported Tuesday. Eight bodies have been recovered.

At least 15 people have been killed and thousands more forced from their homes by flooding in southern and central China, with more rain forecast in coming days.