Twenty people were killed early on Sunday when a packed bus came off the road on a highway west of the DR Congo capital Kinshasa and burst into flames, a local official said.
"The provisional toll is 20 dead," Didier Nsimba, deputy administrator of Mbanza-Ngungu territory told AFP.
The bus, laden with people and goods, was travelling from from Lufu to Kinshasa when the brakes failed, he said.
An injured passenger who gave her name as Nacha said more than 100 people had been in the vehicle at the time, and many bodies were burned beyond recognition.
Mbanza-Ngungu is located about 150 km west of Kinshasa on Highway 1, a road with a notorious reputation for deadly accidents.