Tropical storm Kestana became a typhoon Monday, as it approached China's southernmost island province of Hainan, said the provincial meteorological station.
The station said the storm turned into a typhoon at about 10:00 a.m., when it was monitored 410 km from Hainan, and had strong winds up to 110 km per hour at its eye.
Sanya City, the most famous beach resort on the island, closed all scenic spots and forbade tourists from going sea swimming at noon.
The city, in the south of the island, has also seen 1,567 fishing vessels return to harbor.
Cheng Hong, deputy director of the city's flood control headquarters, said the city has prepared for a possible "frontal attack" of the typhoon.
The provincial meteorological station said the storm's northern section may pass through the southern island on Tuesday.
Kestana has caused severe casualties in the Philippines.