NEW DELHI, Jan. 10 (Xinhua) -- Four coaches of a passenger train caught fire in the eastern Indian state of Bihar Wednesday, railway officials said.

Fortunately, there were no passengers on the train when the fire broke out in four of its coaches at Mokama railway station in the state capital Patna.

Officials said the Patna-Mokama passenger train reached Mokama station late Tuesday night and was stationed in the railway yard of Mokama Station.

"Flames were spotted in two bogies early this morning. It engulfed two more coaches," Rajesh Kumar, East Central Railway spokesperson, told the media.

A probe has been ordered into the incident, he added.

The state-owned Indian Railways is one of the world's largest train networks, criss-crossing the country from north to south, carrying some 23 million passengers daily. But the safety record is poor.

The Indian government has pledged billions to revamp the ailing railways and its colonial-era infrastructure.