Tropical storm Fengshen struck China's southeastern coast Wednesday, bringing new torrential downpours to a region still reeling from heavy rains and deadly flooding since early June.

The storm, which also packed high winds, made landfall in Guangdong province early in the morning, closing schools and disrupting air traffic across the region and in neighbouring Macau and Hong Kong, Xinhua news agency reported.

More than 13,000 ships had already returned to Guangzhou's bustling port in advance of the storm.

Heavy downpours in the nearby city of Zhongshan limited road visibility to just a few dozen metres, forcing some motorists to stop their vehicles, an AFP reporter witnessed.

The Hong Kong Airport Authority said 70 inbound or outbound flights servicing the city were delayed or cancelled due to the storm, Xinhua said, adding that dozens of flights were similarly affected at Chinese airports.

Xinhua quoted the provincial meteorological authority as saying the storm, which had been downgraded from a typhoon after earlier ravaging the Philippines, would move slowly north and gradually lose strength.

However, it was expected to continue to dump heavy rains on areas of eastern and southeastern China that were pounded by deadly downpours since early June.

The rains, the worst in more than a century for some regions, had killed at least 176 people and left 52 missing in flood-related incidents as of last week, according to Chinese state media.

Fengshen's landfall was preceded by heavy gales and the storm was expected to dump up to 200mm of rain on the Guangdong city of Shenzhen on Wednesday and Thursday, Xinhua said.

The China Central Meteorological Station said heavy rains would sweep Guangdong, Fujian, Guangxi, Jiangxi and Hunan provinces for several days.

Fengshen, then a typhoon, left hundreds dead or missing in the Philippines in recent days.