About 20,000 people were evacuated from potentially hazardous areas ahead of the storm, China's official Xinhua News Agency said.Â
Fishing boats returned to port and more than 21,000 crew members came onshore.
A short video posted online by Guangdong Radio and Television showed winds snapping off tree branches and heavily rocking a docked boat and sending waves sliding over the pier.
Kajiki gained strength as it moved west over the sea with maximum sustained winds of 162km/h, China's National Meteorological Centre said.
Rainfall of 25 to 35 centimetres was forecast for southern parts of Hainan Island including Sanya, a popular beach resort.
Sanya shut down businesses and scenic tourist areas and halted public transport and shipping, Xinhua said. A social media post by the city urged residents not to go out unless necessary.
Kajiki, which can mean spearfish or swordfish in Japanese, was expected to make landfall on Vietnam's coast on Monday.
Authorities in Vietnam planned to evacuate more than 586,000 people from the central provinces of Thanh Hoa, Quang Tri, Hue and Danang, where the typhoon is forecast to make landfall, state media reported.
Seven coastal provinces in the Southeast Asian nation banned boats from leaving shore early on Sunday, Tien Phong newspaper reported.
Flag carrier Vietnam Airlines cancelled at least 22 flights to and from central cities on Sunday and Monday. Vietjet Aviation said it was cancelling or delaying flights but did not provide details.
With Reuters
