Typhoon Chanchu is approaching South China's Guangdong Province, with its center located about 640 kilometers south of the boom city Shenzhen Tuesday morning.

The center of the typhoon was located at 16.8 degrees north latitude and 114.9 degrees east longitude at 8:00 a.m. Tuesday and is expected to move northward at 15 to 20 kilometers per hour in the coming 24 hours, said the meteorological station in Guangzhou.

It said the maximum wind speed at its center was 45 meters per second, or 14 on the wind scale.

The typhoon may land in the coastal regions between Shenzhen and Raoping County Wednesday afternoon or Thursday morning, but may also bypass Guangdong and move toward Fujian Province or the Taiwan Strait instead, said Huang Zhong, chief weatherman at the Guangzhou station.

He said the typhoon will bring high wind in seawaters off Guangdong Province as well as rainstorms in most parts of the province and south of the Pearl River Delta starting Tuesday night.

The stormy weather will last until Thursday, he added.

Fujian and Hainan provinces are also being prepared for the typhoon, the earliest and probably the strongest to attack South China at this time of the year.

Hainan Province has called off passenger transport between the island province and Guangdong by sea and by rail.

Chanchu, whose name means "pearl", formed in the northwestern Pacific, about 550 km to the east of Mindanao island in the Philippines on May 9. It hit central Philippines on Saturday, killing at least 32 people and leaving more than 1,000 others homeless.