Two more people died over the weekend from Friday's bus fire on the Third Ring Road while a container of gasoline has emerged as the source of the blaze, according to Chengdu officials.

Investigators have yet to determine if the fire, which injured 74, was an accident or was deliberately set. Of the 72 injured who are still hopitalized, 18 are in critical condition and 54 are in stable condition.

Neither accidental bus fires caused by passengers carrying flammable liquids nor sabotage are uncommon in China.

Municipal officials said that mechanical failure may not be the cause of the fire. Buses in Chengdu are retired after 500,000 kilometers or 10 years – the bus from Friday's fire had been driven fewer than 270,000 kilometers over less than five years.

Last July, two were killed and 14 injured in double bus bombings in Kunming, capital of Yunnan province.

A fire of unknown origin on a bus plying the number 9 route this morning has left more than 20 dead, according to local media reports.

According to city representatives speaking at a 10:00 press conference, this morning at around 8:00 a bus coming in to town from Tianhui Zhen burst into flames on an off ramp on the Third Ring Road's Chuanshan flyover.

The source of the fire is reportedly unclear and is under investigation.

Update: Shanghai Daily is reporting 24 dead and 42 injured as a result of this morning's bus fire. The fire's cause has yet to be determined.

Update 2: The death toll from the bus fire is now at 25 people with a total of 76 injured, six of whom are in intensive care.

Image: www.scol.com.cn