At least 30 people have died and 18 are missing in southern China after days of torrential rain triggered landslides and flooding, state media said Wednesday.

The bodies of the 30 victims were recovered after landslides struck five counties in Guangxi region Wednesday, and rescuers were still searching for another 18 bodies, Xinhua news agency reported.

The landslides were caused by heavy rains that have fallen in Guangxi since Monday, China's official news agency said.

A township in Guangxi's hard-hit Cenxi City recorded 230 millimetres (nine inches) of rain in a 12-hour period ending Wednesday morning, Xinhua said.

In the city of Laibin, two students were reported missing after rising waters engulfed 65 schools late Tuesday and early Wednesday, leaving students and teachers stranded for hours before rescuers could reach them, Xinhua said.

"I woke up at 3:00 am and saw the room was flooded," Xinhua quoted Wei Yanting, a girl who lived on the ground floor of one dormitory, as saying.

"We all climbed on to the top bunk beds and sat there watching the water cover the lower ones."

More than 80,000 people had been evacuated from their homes as of 7.00 pm (1100 GMT) Wednesday, said a notice on the Ministry of Civil Affairs' website.

More than 2.1 million people in Guangxi were affected by the disaster and more than 4,200 homes had been damaged, the notice said.

The ministry said a national committee for disaster relief and Guangxi's regional civil affairs department had begun begun an emergency response plan, allocating 1,200 tents and 1,000 cotton quilts to help settle victims.

Earlier reports said this week's storms over southern China have caused economic damage estimated at nearly 600 million yuan (88 million dollars).

Summer rain storms annually deluge the region, often with devastating results leading to hundreds of fatalities.