Humanitarian Affairs Minister Steve Mbikayi is calling for sanctions against those responsible, adding that the boat was overloaded with passengers and cargo, VOA News reported.
He said night navigation also played a role in the accident.
Mbikayi wrote on Twitter that 300 people survived the accident.
The boat was on a trip from the capital Kinshasa to Mbandaka when it capsized near Longola Ekoti.
Deadly boat accidents are common in the DRC. Boat accidents along the Congo River and its tributaries often end with fatalities because many passengers are not wearing safety vests and because they occur in remote locations where rescue efforts can be delayed.