Authorities said a portion of the bridge in Zhashui County in the city of Shangluo collapsed on Friday evening after recent rains and flash flooding.
As of 12 p.m. local time (12 a.m. ET) Saturday, search and rescue operations were ongoing after 17 cars and 8 trucks fell into the river, state media reported.
Parts of China have been grappling with devastating floods, just weeks after scarce rainfall and sweltering temperatures created drought conditions.
In neighboring Henan province, more than 100,000 people across the province have been evacuated from their homes as a result of flooding, according to state media.