About 30 people are thought to have died when a bus exploded in the southern Chinese province of Jiangxi.
The bus was travelling from the southern city of Shenzhen to the eastern province of Zhejiang when the accident happened early in the morning.
The force of the blast was so violent that it also injured passers-by and damaged nearby homes, reports say.
There have been a number of accidents in China this year caused by the mishandling of explosives.
The practise of keeping dynamite in homes, although illegal, is common in China, and safety measures are often ignored, the BBC's Tony Cheng in Beijing reports.
China's government has recently introduced legislation aimed at reducing the high number of industrial accidents.
At least seven people were injured in the blast that occurred at about 0400 local time near the city of Shangrao, reports say.
Police at the scene said they could not confirm the exact casualty figures because of the destruction caused by the blast, which was heard up to two kilometres (1.2 miles) away.
"I can only tell you that it was a sudden and unexpected explosion," Shangrao city official Huang Hailing told the AFP news agency.
Mr Huang said no survivors were found on the bus which was "completely destroyed".
Police immediately closed the highway just outside of Shangrao to continue their investigation.