China evacuated nearly 400,000 people and called thousands of vessels back to port as a severe tropical storm lashed its southern coast late Wednesday, state media and government agencies said.

Severe Tropical Storm Kammuri made landfall in China's Guangdong province, packing strong winds, the local weather observatory was quoted as saying by the official Xinhua news agency.

There were no immediate reports of damage, Xinhua said.

The storm was expected to later head west along the densely populated coast, according to the website of the China Meteorological Administration.

Kammuri hit Hong Kong earlier Wednesday, unleashing winds of 110 kilometres (68 miles) per hour at its centre, according to the Hong Kong Observatory.

The ferocity prompted Chinese officials to step up the emergency response level.

Guangdong, along with neighbouring Hainan island and Guangxi's Zhuang region, decided to evacuate 388,000 people from their homes, Xinhua said.

The three areas also ordered a total of 57,800 vessels back to port, according to Xinhua.

"(We should) ensure all these people be evacuated to safe places in order to guarantee the people's lives," Chen Lei, the minister for water resources, said in a statement on the department's website.

Torrential rain has affected huge parts of southern and central China in recent months, taking a heavy toll in life and material damage.