Five people have died and four injured in a traffic acccident on a highway in southwest China's Yunnan Province, local authorities said Tuesday.

The accident took place about 1 p.m. Monday in Yao'an County when a mini-bus carrying nine people veered off the highway into a ditch.

Four injured people are being treated at a local hospital and are in stable condition, a county government spokesman said.

Local police are investigating the cause of the accident, he said.