CHENGDU -- Six people were killed and five others injured in a traffic accident in Chengdu, capital of Southwest China's Sichuan province, early Tuesday morning, local police said in a statement Thursday night.

The crash occurred around 4:37 am when an overloaded minivan collided with a parked semi-trailer. All injured people have been treated and are now in stable condition.

After an investigation into the cause of the accident, the driver of the minivan and three personnel from the company to which the minivan belonged were detained. Police are also investigating possible violations by the semi-trailer driver.