NAIROBI, Kenya — At least 50 people were killed and more than 100 suffered burns in the Democratic Republic of Congo on Saturday when a tanker truck collided with a bus and caught fire, officials said.

The fire broke out just as local residents had reached the scene to gather leaking fuel, lifting the number of casualties. The accident occurred near the eastern city of Kisantu, about 125 miles south of the capital, Kinshasa.

Séguin Singuela, the Kongo Central police commissioner, said the accident occurred late in the day and could have been a caused by visibility problems. He said a third vehicle crashed into the accident scene and also caught fire.

Atou Matubuana, the interim governor of Kongo Central Province, said officials would assist the wounded and help take care of the dead. The central government dispatched a team led by the transportation minister.