Eight people were reported dead in Wuhan, in Hubei province, with 280 injured after Friday's tornado ripped through the district of Caidian at 8:39 p.m., the agency said.
The tornado toppled 27 houses and damaged 130 more, as well as two tower cranes and 8,000 sq. m. (86,111 sq. ft) of sheds at construction sites, it added.
"I've grown up in Wuhan and I've never seen anything like it," one resident of the city posted on China's Weibo app. "There's been so much extreme weather recently."
Another tornado struck the town of Shengze, in the Suzhou area of tornado-prone Jiangsu province, killing four people and injuring 149, Xinhua said.
Fire officials said the winds damaged electricity facilities and toppled several factory buildings, it added.
Tornadoes often hit Jiangsu in the late spring and early summer.
China's commercial hub of Shanghai, 100 km (62 miles) from Suzhou, was also hit by powerful thunderstorms, prompting weather officials to declare an alert.
More heavy storms were expected in Shanghai and other parts of the Yangtze river delta region later on Saturday, the state weather forecaster said.
China faces more extreme weather as a result of climate change, Jia Xiaolong, an official of the forecaster, told reporters late in April, adding that the risk of disasters such as heat waves and floods was expected to rise in coming years. (Reuters)