Eleven people are missing following storms that battered southern China, state media said Monday, with tens of thousands evacuated away from the torrential downpours.

Heavy rain has descended upon the vast southern province of Guangdong in recent days, swelling rivers and raising fears of severe flooding that state media said could be of the sort only "seen around once a century".

"A total of 11 people are missing after continuous heavy rainfall hit many parts of (Guangdong) in recent days," state news agency Xinhua said, citing the local emergency management department.

More than 53,000 people have been relocated across the province, it added.

Of those, more than 45,000 were evacuated from the northern Guangdong city of Qingyuan, which straddles the banks of the Bei River, a tributary in the wider Pearl River Delta, state media reported Sunday.

Heavy rain is expected to continue on Monday, with meteorological authorities forecasting "thunderstorms and strong winds in Guangdong's coastal waters" -- a stretch of sea bordering major cities including Hong Kong and Shenzhen.

Neighbouring provinces, including parts of Fujian, Guizhou and Guangxi, will also be affected by "short-term heavy rainfall", the National Meteorological Centre said.

"It is expected that the main impact period of strong convection will last from daytime until night," it added.

Guangdong province is China's densely populated manufacturing heartland, home to around 127 million people.

In the town of Jiangwan, six people were injured and a number were trapped in landslides caused by heavy rain on Sunday, state media reported.

Photographs published by state broadcaster CCTV showed waterfront homes destroyed by a wall of brown mud, and people sheltering in a soaked public sports court.

CCTV reported Sunday that floods as high as 5.8 metres (19 feet) above the warning limit would strike in Pearl River tributaries on Monday morning.

China is no stranger to extreme weather but recent years have seen the country whiplashed by severe floods, grinding droughts and record heat.

Climate change driven by human-emitted greenhouse gases makes extreme weather events more frequent and intense, and China is the world's biggest emitter.