More than 100,000 people were affected – mostly in the epicentre at Changning county in
Land subsidence and a landslide caused by the earthquake, which had a magnitude of 6.0, have blocked a highway, several major roads and numerous village roads, the statement said, while a major bridge in the area is also at risk.
The Yixu highway in Changning has been closed and authorities are currently assessing the Dongdi Bridge. The Yibin government statement also said workers had been sent to clear the affected village roads.
According to the US Geological Survey, the earthquake was centred at a fairly shallow depth of 10km (6 miles). Shallow earthquakes tend to cause more damage to buildings and infrastructure.
An aftershock measuring magnitude 5.2 later hit the same area, the USGS said.
More than 300 firefighters were sent to the scene overnight, as well as rescue personnel with 5,000 tents, 10,000 folding cots and other emergency supplies, according to Xinhua.
A 1976 earthquake centred in the northeastern city of Tangshan killed at least 250,000 people.