At least two vehicles plunged into a river after part of a bridge collapsed in the urban area of Heyuan City, south China's Guangdong province early Friday, according to the local road management authorities.

One person was rescued, but the exact casualties remain unknown as the search and rescue work is underway.

Heyuan is among areas worst hit by flood in Guangdong due to persistent heavy rains over the past week. The rain began to weaken in the province.