Rice is a staple for most Chinese and a crop which needs a constant supply of water

The Gan and Xiang rivers running through the two provinces had seen their lowest water levels in history, Xinhua said. The shallow water has caused a jam of barges in some sections of the Gan.

Authorities had rushed to ensure drinking water supplies in big cities along the rivers and irrigation of fields by diverting water from reservoirs and installing pumps, Xinhua said.

Water levels on China's longest river, the Yangtze, and on the Pearl River in the southern province of Guangdong had also dropped, Xinhua said.

Drought and floods are perennial problems in China where meteorologists have complained about the increased extreme weather, partly blaming it on climate change.

More than 1,100 Chinese were killed during summer floods this year.

But some parts of the south were hit by weeks of scorching heat and drought in the summer, when as much as a third of farmland was damaged and millions of people were short of drinking water.

It was not immediately clear how much damage had been caused to the rice crop.