KINSHASA, Democratic Republic of Congo — Dozens of people drowned after a boat tipped over in the northern Democratic Republic of Congo, officials said on Friday.

The vice governor of Tshuapa Province, Richard Mboyo Iluka, said the boat was carrying passengers to the city of Mbandaka from Monkoto on Thursday when it capsized just outside Wafania, killing 49 people.

Mr. Iluka said that investigators had been sent to the area to assess the situation and confirm the death toll. He said he did not know how many people had been on the boat at the time of the accident, how many survived, or what might have caused the vessel to sink.

Deadly boat accidents are common in Congo, a vast, forested country that has few roads outside of major towns and that is carved up by a network of rivers that drain the Congo Basin. For most people, these rivers are the only means of traveling long distances.