Storm hits Hong Kong
The storm struck Hong Kong early Wednesday with winds of up to 195 kph (120 mph), toppling trees, flooding coastal neighborhoods and forcing people to seek refuge in temporary shelters.
Authorities reported at least 13 injuries and suspended flights, schools and train services.
The storm also caused infrastructure damage as it ripped off the top of a pedestrian footbridge.
The Hong Kong Observatory warned of a "significant" storm surge with "two to three meters of rise in water level expected over the coast of Hong Kong."
Earlier, the observatory issued the highest level of typhoon warning overnight.
South China braces for landfall
Meanwhile, Ragasa forced the relocation of more than a million people in southern China's Guangdong province.
The storm is forecast to make landfall later on Wednesday between the cities of Taishan and Zhanjiang, according to the national weather agency.
Chinese authorities have ordered businesses and schools to shut down in at least 10 cities across the south.
Ragasa has battered the region since Monday.
In the northern Philippines, three people have been killed, with thousands displaced by floods and landslides, officials said.