A train carrying about 1,700 passengers caught fire in a tunnel on the Lanzhou-Xinjiang rail line at 8:15 am Sunday morning, according to Chongqing Evening Newspaper. No injuries were reported.

Railway staff rush a faint train attendant to hospital after a train carrying about 1,700 passengers caught fire in a tunnel on the Lanzhou-Xinjiang rail line at 8:15 am Sunday morning. [Huashang News]

Train K1043 was headed for Urumqi, capital city of Xinjiang Uygur Autonomous Region, from Xi'an, capital city of Shaanxi province. The front of the train caught fire as it was driving through the Wuqiaoling Tunnel—the longest railway tunnel in China at 20,500 meters— and was immediately pulled to a full stop. The train head was 2,000 meters near the west tunnel exit.

All passengers on board were evacuated and guided by train staff out of the dark tunnel.

"It seems like we walked a long time in the tunnel, and my legs didn't feel like mine after I came out," a passenger surnamed Liang told reporters. "Many passengers' faces turned black by the fumes in the tunnel."

The cause of the incident is now under investigation.