LA PAZ, April 11 (Xinhua) -- At least seven people died and nearly 30 were injured after a bus overturned on a highway in southwest Bolivia, local authorities said Thursday.

The bus, belonging to the company Trans Tupiza, overturned on its left side at the Pan American Highway on the Oruro-Potosi stretch.

As a result, the bus sustained heavy damages to the left side and passengers riding on that side suffered the worst impact.

The injured were taken to hospitals in Challapata and Oruro, according to local officials.

The cause of the accident is still unknown.