Live images show a bus burst into flames after it caught fire in Yizhang County of Hunan Province on Sunday morning.[Photo/Weibo]

A fire that reduced a tour bus into charred frames on Sunday morning has killed at least 35 people, including two children, in Hunan Province, local authorities said.

The bus was carrying 55 people, the county government of Yizhang said, correcting the previous report saying 56 were on board. Eleven people were hospitalized, including four seriously injured.

The accident happened at about 10:20 a.m., when the bus crashed into the guardrail on a highway in Yizhang. The ensuing oil leak caused the fire, according to the government.

A photo taken at the site shows huge clouds of black smoke rising from the vehicle, and another shows the black skeletons of the bus after fire was put out.

State Councilor Guo Shengkun, who is also public security minister, has ordered all-out efforts to save the injured, identify the cause of the accident, and to take measures to prevent similar tragedies from happening again.

A work team headed by Vice Public Security Minister Huang Ming is heading for Hunan to guide the investigation and handling of the accident on site.

Police have detained the driver.