Chinese President Xi Jinping urged all-out rescue efforts after a motorway bridge collapsed on Friday in Shaanxi province in the north-west of the country, killing at least 11 people, state media reported on Saturday.
The incident occurred at 8.40pm local time in Shangluo city when flash flooding caused the bridge to collapse, throwing vehicles into the river.
On Saturday morning, five vehicles were confirmed to have fallen into the water and 30 people were reported missing, state media said.
Mr Xi said China is in a critical period for flood control and local governments must take responsibility to enhance monitoring and early warning.
China's national fire and rescue authority said on Saturday it had sent a rescue team to the site that included 859 people, 90 vehicles, 20 boats and 41 drones.
In Sichuan province in the south-west of China, an estimated 30 people were missing and about 40 houses wrecked in flooding and storms, Xinhua news agency reported.
It said roads, bridges and communication networks in the hardest-hit Hanyuan county had been damaged or knocked out and that rescue teams had been working since before dawn to restore communications and transport connections.
China's western and southwestern provinces are particularly prone to flooding and landslides given their mountainous landscapes and the powerful rivers that run through them. Mining, tourism and rising urbanisation have also disturbed a precarious balance with the natural environment that had been sustained over thousands of years.
Shaanxi is best known as one of the fulcrums of Chinese civilisation, from which emerged the first emperor, Qinshi Huangdi, who left the famed terracotta army as his legacy outside the capital Xi'an as part of a vast tomb complex that attracts a great many visitors each year.
With reporting from agencies …