XI'AN - Six people were killed and two others injured after an accident early Wednesday morning in an expressway tunnel in Northwest China's Shaanxi province, local authorities said on Thursday.

The accident occurred at around 2:20 am in the Liushililiang tunnel on the Fuyin expressway, which links Fuzhou, capital city of Fujian Province, and Yinchuan, capital city of Ningxia Hui Autonomous Region.

Two heavy-duty trucks collided in the tunnel, blocking traffic on the road.

A freight truck driving into the tunnel crashed into three cars which were stopping behind the two heavy-duty vehicles.

The cars and the freight truck caught fire, leaving six people dead and two others injured.

The injured were sent to a nearby hospital and are in stable condition.

The accident has caused damage to parts of the tunnel, and police said traffic will hopefully resume back to normal on Thursday afternoon.