(CNN) -- A bus caught fire in the southeastern Chinese city of Xiamen on Friday, killing at least 42 people and injuring 33 others, the state-run news agency Xinhua reported, citing local officials.
The vehicle was on an elevated bus lane and more than a quarter-mile from a bus stop when the flames started about 6:30 p.m., an official in the coastal city told Xinhua.
It wasn't clear what started the fire. Witnesses said they heard explosions 10 minutes after the fire started, according to Xinhua.
A picture of the bus on Xinhua's website showed a badly charred interior. An injured passenger told Xinhua that she smelled gasoline while on the bus and then saw a fellow passenger breaking a window in an attempt to get out.
The incident is under investigation, Xinhua reported.