Evacuations as typhoon swirls into China

More than 600 trees fell and pieces of buildings were seen crashing into downtown streets as commuters made their way home from work. (AAP)

More than 600 trees fell and pieces of buildings were seen crashing into downtown streets as commuters made their way home from work. (AAP)

Concerns about Typhoon Vicente have prompted China to evacuate more than 42,000 people and prepare for possible flash floods and other disasters.

The strongest typhoon to hit Hong Kong in 13 years has swirled into southern China after injuring dozens of people and disrupting transport.

Although downgraded to a tropical storm, it has still led to the evacuation of more than 40,000 people in one city.

Vicente left Hong Kong on Tuesday morning.

The stock exchange resumed operations in the early afternoon. Flights at Hong Kong airport and public transport were returning to normal.

Chinese state media said that even in its weakened state, the storm could dump 300mm of rain on Guangxi province, after it passes through Guangdong.

They said authorities had evacuated more than 42,000 people in the Guangdong city of Maoming, and begun preparations to cope with possible "flash floods, mudslides, landslides and other disasters".