Chinese state media said 36 people were killed when a bus collided with a methanol tanker in northwest China and burst into flames.
Three passengers survived the crash near Yanan, Shaanxi province and were being treated in hospital, the official Xinhua news agency said.
An investigation team set up by China's State Council was dispatched to the accident site to help with the investigation.
The 39-seat sleeper bus was full at the time of the crash, which occurred close to a service station on the Baotou-Maoming Expressway linking northern China's Inner Mongolia Autonomous Region and Guangdong Province in the south.
The driver and passenger of the tanker were not injured.
Traffic accidents are among the leading causes of death in China, according to public health officials.
State media reports citing police figures say about 100,000 people have been killed in traffic accidents annually over the past decade, with the figure dipping to 70,000 last year.
