At least two people were killed and over ten injured when an airport shuttle bus in Changsha, capital city of central China's Hunan Province, caught fire Wednesday, police said.

The bus caught fire near an expressway tollgate as it traveled from Changsha's Huanghua International Airport to the city proper at about 4:00 p.m. Wednesday, police said.

The injured were rushed to a local hospital.

It is not known how many people were aboard the bus.

The front of the bus was completely destroyed and many parts of the cabin were burnt. The bus's windows were shattered and glass shards lay scattered on the road, according to Xinhua reporters at the scene. The pungent smell of gasoline still lingered in the air hours after the blaze.

Police have cordoned off the area and tightened airport security, including by searching passengers boarding shuttle buses.

The cause of the fire is being investigated. But some witnesses told Xinhua they believe it was arson.

Peng Haibo, a witness at the scene, said he saw the bus engulfed by flames and thick smoke as terrified passengers jumped out of the bus's windows to escape the inferno.

Another witness who gave her surname as Chen said a passenger told her somebody lit a red-striped bag and kicked it toward the bus driver's seat just before the fire.

"He said he thought the man who set lit the bag must have been a terrorist so he opened the window and jumped out," Chen said.

Many bloggers on Sina.com, a popular Chinese Internet portal, expressed shock at what had happened.

"Goodness me! I have ridden the airport shuttle bus many times. I hope it was not a terrorist attack," said one posting.