Twenty-four people were killed Monday and seven others injured when a bus crashed through a guardrail and plunged 30 meters (100 feet) off an overpass in southwestern China, state media reported.
Xinhua News Agency said slippery roads may have caused the bus driver to lose control.
It said five of the injured were in critical condition in a Chongqing hospital, and that police were still trying to determine the number of passengers on the bus.
China's roads are among the world's most dangerous, with thousands of people dying each year in accidents caused by reckless driving, poor road conditions and overloading of vehicles.
Last October, a bus drove off an on-ramp of a Chongqing bridge, killing 30 people and injuring 20.