Seven people have been confirmed dead and 48 others injured in a traffic accident in Guizhou Province, local authorities said Thursday.

The accident occurred at about 8 a.m. in the city of Zunyi, when a coach heading for Nanchong City in Sichuan Province smashed through the guard bar and overturned. Seven of the 55 people on board died at the scene, including the driver.

The 48 injured, 21 seriously, had been sent to hospitals in Zunyi, local authorities said.

The cause of the accident is under investigation.