Eleven of the deaths were attributed to a tornado that spun off the typhoon, wrecking houses and injuring more than 60 residents in China's Zhejiang Province, Xinhua state news agency reported.
"The bizarre wind smashed all the windows of our four-storey building and tore down my mum's old house in no more than one minute," the agency quoted 48-year-old villager Zhang Zhongling as saying. "Just like a hurricane."
More than 900,000 people in southern China have been relocated to higher ground after the typhoon cut power and flooded homes in parts of Taiwan and the Philippines on Saturday.
Sepat is heading northwest toward Jiangxi Province and could unleash 400 mm (15.75 inches) of rain in southern Fujian province in the next three days, said Xinhua.
The storm destroyed hundreds of homes and cut off power from Fujian in the south to Zhejiang in the east of the country.
However, Xinhua reported relatively light economic damage of only $42 million across the country.
Typhoon Sepat did not make landfall over the Philippines but exacerbated monsoon rains as it rumbled past the archipelago.
Disaster officials in the Philippines said three people drowned in flooding. Nearly 550,000 people were affected by floodwaters in Manila and the northern provinces, and more than 3,500 people were sheltering in evacuation centres.
Taiwan's disaster centre said 27 people had been hurt in the typhoon, which cut power to more than 70,000 homes and forced airlines to delay flights from the north and south of the island.
- Reuters - Thomson Reuters Foundation
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