Authorities have arrested a man suspected of setting fire to a bus in Xiamen, Fujian province, injuring himself and 11 others, the local public security bureau said.  

Five passengers suffered burns, three others and the bus driver were hurt by broken glasses, while the rest were hurt when they tried to jump off the bus. The oldest victim was a 77-year-old passenger.

The 53-year-old suspect from Henan Province surnamed Cai was arrested on the spot.

"The man [suspect] stabbed two people before he was captured by the police. He then began to stab himself," a witness surnamed Wang told the Global Times Thursday.

The crowded bus caught on fire on its regular route on Thursday morning.

"Someone knocked over a bottle of some transparent liquid around the bus door, which emitted black smoke. Then the bus was filled with a foul odor and some passengers tried to break the bus windows with the emergency hammers," a passenger on the bus surnamed Luo told the Global Times.

The driver stopped the bus to let the passengers off. He called the police after the fire was extinguished, Luo added.

Cai is also being investigated for another arson case earlier Thursday at the Huangzehe Food Company, which caused no injuries, local police said. Cai was an employee of the company before being fired for theft on Wednesday.