BEIJING, May 5 -- An arson suspect was detained on the spot on a bus en route from Beijing's outskirts to downtown area on Tuesday morning. No casualties were made.

A man splashed unknown liquid in No. 814 Bus, when it was approaching a toll gate in Tongzhou District of Beijing at around 7:40 a.m.

The bus driver was alerted by the odor of the liquid and the man's action. He pulled up the vehicle by the road side. As he helped evacuate passengers, the man ignited the liquid to cause fire in the bus.

The driver called police and joined the bus conductor to catch the suspect.

Police are investigating the case of arson.