Deluges in Guizhou -- classified as a southwestern province by the Chinese government -- have prompted authorities to activate the highest-level emergency flood response, evacuating around 80,900 people by Tuesday.

On Thursday state broadcaster CCTV said "exceptionally large floods" had swept through Guizhou's Rongjiang county since Tuesday.

"As of 11 am on Thursday... six people have unfortunately lost their lives," the report said, citing the local flood control headquarters.

"Many low-lying areas in the county were flooded, and the infrastructure of some towns was seriously damaged, resulting in traffic obstruction, communications blackouts, and some people being trapped," the broadcaster said.

"The water level in the county has now retreated below the warning level," it added, saying "post-disaster recovery and reconstruction and investigation of trapped people are underway".

Xinhua reported Wednesday that a football field in Rongjiang was "submerged under three meters of water", and a resident told the news agency they were rescued from the third floor of their home.

Guangxi, a region that borders Guizhou, has also been hit by torrential rains, with Xinhua publishing photographs of mud flowing onto residential streets in Meilin Township.

Flood alarms have been triggered along 20 rivers running through Guangxi in recent days, Xinhua reported.

Landslides and flooding have damaged communications infrastructure in the region, with Guangxi's telecommunications authorities vowing to "actively communicate and share information" with other government departments for disaster relief.

China is enduring a summer of extreme weather.

This week, authorities issued the second-highest heat warning for the capital Beijing on one of its hottest days of the year so far.

And tens of thousands of people were evacuated last week in Hunan province -- neighbouring Guizhou -- due to heavy rain.