Two of the victims, an 80-year-old woman and an 11-year-old girl, died in a mudslide in Shenzhen on Sunday, and the third was killed in Zhuhai by an aluminum sheet that was blown off a roof by high winds, Xinhua news agency reported.
More than 1.3 million people have been affected on Hainan Island, a popular tourist resort. Some 213,000 of these have been evacuated, and 550 houses have been destroyed. Local authorities have estimated the damage at $48 million.
Neoguri, the earliest typhoon to hit China in more than half a century, slammed into the south of the country with heavy rains and strong winds on Friday, and then weakened to become a tropical storm.
The first typhoon in China usually comes in late June.