SAN FRANCISCO - Five Chinese citizens were killed and eight others injured in a traffic accident near Yellowstone National Park in the US state of Idaho Thursday evening, the Chinese Consulate General in San Francisco confirmed on Friday.

The accident occurred on a highway near Henry's Lake State Park, about 26 km west of Yellowstone National Park, the Idaho State Police said in a press release.

A pickup truck and a tour van collided and burst into fire, the police said.

The cause of the accident is under investigation, the consulate told Xinhua.

The consulate expressed deep condolences for the dead and sincere sympathy to the injured and the families of those affected.

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It has promptly activated its consular protection emergency response mechanism to provide assistance and support to the injured and the families of the deceased.

The consulate is also working to ensure proper medical treatment for the injured and to help the families of the victims with follow-up arrangements. It pledged to continue doing its utmost in handling the aftermath of the incident.

The consulate has requested the US authorities to conduct a thorough investigation, verify the situation, and formally report the findings to the Chinese side.

The Idaho State Police said the driver of the pickup truck died and there were casualties among the passengers in the tour van.