China is bracing for the imminent landfall of Typhoon Doksuri, shutting schools and businesses in some coastal cities, while its national observatory renewed its most severe weather alert after overnight heavy rainfall in the country's southwest.
The approaching typhoon is expected to make landfall on China's southeast coast in the early hours of Friday, state radio reported, citing Fujian provincial weather authorities.
China's national observatory has classified Doksuri as a "strong" typhoon, with maximum winds of 180 kilometres per hour, as it hurtled northwest through the Taiwan Strait towards Fujian province as of 12pm (0400 GMT) Thursday.
At one point, Doksuri was a super typhoon but lost some of its strength after it lashed the coastline of the northern Philippines on Wednesday, bursting banks of rivers and leaving thousands without electricity.
Doksuri killed five people in the Philippines, according to the country's disaster agency.
Three coastal cities in Fujian province shut schools, businesses and factories on Thursday, state media reported, while flood control authorities in one of them, Xiamen, warned of a "serious impact".
However, the China Meteorological Administration forecast it would be weaker than 2016's Typhoon Meranti, which killed at least 11 people and was the strongest to hit China's eastern coast since 1949.
Fifteen provinces and city-level administrative units across China have been affected by "severe" weather including thunderstorms, heavy rainfall, gales and hail ahead of Doksuri's landfall, state media Xinhua reported.
Beijing launched emergency flood control operations in the country's southwest on Wednesday night after torrential rains in the provinces of Sichuan, Guizhou and Yunnan as well as the nearby metropolis of Chongqing.
Heavy flooding in the city of Luzhou, Sichuan province, swept cars onto tree trunks, according to videos circulating on Chinese social media.
Passenger ships and fishing boats have also been grounded in parts of coastal Zhejiang province immediately north of Fujian.
Businesses and schools were shut in southern Taiwan on Thursday and airlines cancelled hundreds of flights amid warnings of landslides and floods as Doksuri churned past the island en route to China.
Taiwan's weather bureau issued wind and rain warnings on Thursday for the southern and eastern parts of the island, including the major port city of Kaohsiung.
All domestic flights and ferry lines were suspended in Taiwan while more than 100 international flights were cancelled or delayed.
Railway services between southern and eastern Taiwan were shut.
More than 5700 people were evacuated as a precaution, mostly in the mountainous southern and eastern Taiwan, where more than 0.7 metres of rainfall was recorded in some areas and up to a metre of rain was forecast.
The storm had cut power to more than 49,000 households across Taiwan but the majority of them had since been restored.
"Typhoon Doksuri should not be underestimated," Kaohsiung city mayor Chen Chi-mai said in a Facebook post late on Wednesday.
"The police and military force will assist in the effort of forced evacuation if needed," he said, pointing to the threat of torrential rain in mountainous areas.
Braving occasional showers and winds, Taiwan's armed forces pressed ahead with a large-scale anti-landing drill on a beach near the major Taipei Port just outside the capital, simulating the repulsion of an enemy force with ground troops and tanks amid high military tensions with neighbouring China.
The storm has disrupted parts of Taiwan's main annual Han Kuang exercises and air-raid drills that started on Monday, as authorities cancelled some exercises citing safety concerns and the need to make preparations for the typhoon.
