Nineteen people were killed and 31 were missing after torrential rains brought flash floods to remote towns of southwest China, state media said on Wednesday.

Rainstorms hit Wangmo county in the mountainous province of Guizhou on Monday night, triggering torrents of water that brought houses down, the Beijing News said.

"The preliminary tally showed that 19 people were killed and 31 went missing," the newspaper said, adding that transport and communication links to Wangmo were cut off.

South China is usually hit by floods in the summer months, but state media reports say this year's rainfall has been unusually high.

The provinces of Guangdong, Fujian, Guangxi and Jiangxi have taken the brunt of the rainstorms since late May, with floods, landslides and house collapses claiming about 100 lives and forcing the evacuation of hundreds of thousands of people.