CHANGSHA - A section of a highway running near a major river in central China's Hunan Province caved in early Thursday, engulfing a passing vehicle and killing at least one person aboard.

The cave-in, near the Poly International Plaza along the central section of Xiangjiang Road in the provincial capital Changsha, created a 30-square-meter pit on the road.

The depth of the pit was not immediately known, said a rescuer with the local fire brigade. "But we cannot see the bottom of the pit with naked eye."

He said the pit engulfed a passing car and at least one person on board died at the scene.

Authorities did not describe the ill-fated car or identify the victim. But an unnamed witness said it was likely a BMW carrying three people.

The cave-in site was close to the Xiangjiang River, a major tributary of the Yangtze, China's longest waterway.

It was unclear what caused the accident.

The local traffic police had closed the road following the accident. Rescue work continued Thursday morning.