Rainstorms battering southern China have killed at least seven people and allowed dozens of crocodiles to escape from a farm.

Nearby residents were advised to stay at home after more than 70 crocodiles escaped in Maoming, a city near the coast in western Guangdong province, according to mainland media reports.

An emergency official was quoted as saying that 69 adult crocodiles and six juveniles had escaped.

Some have been captured, but the operation was difficult because of the depth of a lake they are in, the media reports said. No injuries have been reported.

Further west, seven people died and three are missing after multiple landslides in the city of Yulin in the Guangxi region, Xinhua News Agency reported late on Monday.

In the south near the coast, Beihai city was inundated from widespread downpour.

Rescuers were seen treading thigh-deep in waterlogged areas evacuating residents in boats. About 1,360 people were trapped on Tuesday, state media said.

The city's observatory raised its storm warning to the highest in a four-tier alert system after more than 101mm rain poured in a three-hour period on Tuesday morning.

The China Meteorological Administration forecast heavy rains in the south and southeast parts of Guangxi on Tuesday and Wednesday, with storms in the southwest. Localised hourly precipitation could hit 70mm in some areas, it added.

Scientists warn that typhoons hitting China are becoming more intense and their paths growing more complex, escalating risk of disaster, even in coastal cities such as Shenzhen that already have strong flood defence capabilities. (AP/Reuters)