At least 32 people were injured when a city bus caught fire in Hangzhou, the capital of Zhejiang province, during rush hour yesterday, police said.
The cause of the fire is still being investigated but local media reported it was possibly an act of arson.
Hangzhou police said 80 people were on board the bus when it caught fire near the scenic West Lake at 5pm.
According to Zjol.com.cn  the news website of the provincial government, at least 24 people suffered severe injuries and were being treated in three hospitals.
At the city's People's First Hospital, where 16 were being treated, dozens of police had been deployed to maintain order, Zjol.com.cn  said.
It cited a witness as saying the fire spread quickly after a quarrel broke out at the back of the bus.
With smoke billowing, the vehicle finally came to a stop. The front door opened but the emergency exits initially did not. Two passers-by managed to break the windows along the side of the vehicle and helped passengers to safety.
Shopkeepers from a nearby mall brought out extinguishers, the Zhejiang Daily said on Weibo.
Witnesses posted their photos of the incident on the Hangzhou Daily's Weibo account and the websites of other local media outlets.
They show panic-stricken people who had managed to escape from the bus, many of them with black smudges on their faces. One photo showed a man who had suffered burns lying on the ground.
Hangzhou Daily cited witnesses as saying the bus engine showed no sign of fire. The bus driver was unhurt, and damage to the vehicle was not serious.
The bus company had been asked to help with the police investigation, it said.