During one fateful week in June 2000, terror gripped the town of Kisangani in the Democratic Republic of the Congo, as fighting between the armies of Rwanda and Uganda left thousands dead, injured, or disabled. Years on, the harrowing bloodshed, named the “six-day war” by local people, remains a taboo topic. Shedding light on the plight and resilience of the survivors, prolific documentarian Dieudo Hamadi follows their tireless mission for reparations, as they set sail to the capital Kinshasa where they will present their demands to the government.

Shot in intimate closeup, the difficult journey constitutes the film’s emotional centre. Avoiding maudlin sentimentality or voyeuristic ethnography, these boat sequences offer an unvarnished, clear-eyed look at the interpersonal dynamics of a marginalised community in which both solidarity and discord coexist. Conflicts are inevitable; the survivors are crammed on to a rudimentary wooden barge with plastic tarps as their only shield from torrential rain and other harsh weather conditions. At one point, one man loudly laments the quality of the food provided by the women, to their dismay. Against these moments of tension, a shared resolution in seeking compensation from a negligent system emerges as a uniting force, one that cuts across private differences.

The brutal reality endured by the disabled victims – which includes inadequate prosthetics, financial precariousness, familial maltreatment, and more – is punctuated with scenes from a play written and performed by the survivors themselves. This radical, formally inventive interplay between documentary and fiction embodies the full sweep of political resistance: against the obstacles of political indifference, the film sees the path towards revolution and justice as one that brings together direct action and creative expression.

• Downstream to Kinshasa is on True Story from 29 March.