HONG KONG (AFP) -- Super typhoon “Yagi” threatened Friday to be the strongest storm in over a decade to hit heavily populated areas of southern China, while tens of thousands of people also prepared to seek shelter in neighboring Vietnam.

The storm made landfall on southern China’s Hainan island on Friday afternoon, bringing windspeeds exceeding 234 kilometers per hour, the state-run Xinhua news agency said, citing authorities.

The ministry of water resources on Thursday raised its emergency response to flooding in both provinces to the third-highest tier.

“Yagi is likely to be the strongest typhoon to hit China’s southern coast since 2014, making flood and prevention work very challenging,” Xinhua said, citing a meeting held by flood officials.

Packing wind speeds of more than 240 kilometers (kms) per hour, the typhoon “is equivalent to a Category 4 hurricane,” according to NASA Earth Data.

In Hong Kong, a typhoon warning that had been in effect was lowered shortly after noon following heavy rains overnight as “Yagi” passed within 400 kms of the city.

Trading at Hong Kong’s stock exchange was suspended on Friday, and day schools were closed.

Authorities said five people were injured in the city due to the weather, but damage was limited.

After moving through southern China, “Yagi” will head towards Vietnam, on course to hit the northern and north-central regions around the famed UNESCO heritage site Halong Bay on Saturday.

Tens of thousands of people will be evacuated to safer areas in Hai Phong and Thai Binh provinces on Friday, local authorities said.

“This will be the strongest typhoon (to hit northern Vietnam) in 20 years,” said Pham Duc Luan, head of the dike management authority on Thursday.

More than 457,000 military personnel have been mobilized by the relief and rescue department of the defense ministry.

Officials have also directed 50,000 fishing vessels carrying 220,000 people to take shelter.