A typhoon that slammed in eastern China's coast Wednesday flooded and washed out roads, knocked out power and disrupted transportation in one of the nation's most populous regions.

Damage to roads and bridges stranded hundreds of people though no casualties were immediately reported, the official Xinhua News Agency reported.

Typhoon Haikui came ashore in Zhejiang province with winds up to 150 kilometres per hour early Wednesday and was weakening.

Shanghai Public Weather Service said Haikui dumped as much as 58 millimetres in one hour in the city's centre in the afternoon.

In Zhejiang, 12 townships lost power. Flooding left at least 130 people stranded in three hotels in Lin'an city after roads were washed out. In Anji county, about 300 tourists were trapped after a bridge was destroyed, Xinhua said.

The China Meteorological Administration had issued a red alert for Typhoon Haikui, the highest alert so far this year. More than 1.8 million people were evacuated from parts of heavily populated Shanghai and neighbouring Zhejiang.

Shanghai, which has 23 million people and is the country's financial hub, banned many outdoor activities. It curtailed public transit, cancelled more than 500 flights, and halted at least 600 trains on Wednesday, local media said.

The city relocated 374,000 residents and Zhejiang evacuated more than 1.5 million people, Xinhua said.

China is still recovering from typhoons Damrey and Saola, which hit over the weekend and caused at least 23 deaths. Saola also battered Taiwan and the Philippines and was blamed for about 60 deaths in the two countries.