GUIYANG - Four people were killed and five others injured in a road accident in Southwest China's Guizhou province on Tuesday morning, said local authorities.

The accident happened at about 10:30 a..when a truck collided head-on with a medium-sized bus with nine people onboard in Liupanshui city.

Three bus passengers were killed at the scene, and another one died on the way to a nearby hospital. Five others were injured, sources with the Liupanshui fire brigade said.

The driver and the only passenger on the truck were unhurt, and joined the rescue work after the accident occurred, according to firefighters.

A further investigation into the accident is under way.