Today marks 25 years since the onset of the Rwandan genocide. In just 100 days, between 7 April and 15 July 1994, seven in 10 Tutsis living in Rwanda were murdered by their Hutu neighbours. As many as 1 million people, including 10,000 Batwa pygmies, died.

What’s less well known about those terrible months is that up to 250,000 women were raped. Many were infected with HIV and later died of Aids-related illness. The UN estimates that 2,000 women became pregnant (the actual number could be much higher). A quarter of a century later, while many of the surviving children of those pregnancies are older now than their mothers were at the time, a great deal of anguish, tension and social stigma persists.

The German photographer Olaf Heine, together with the aid organisation Ora Kinderhilfe, spent three years working on the Rwandan Daughters project, which portrays 80 rape victims and their children (seven sons also feature). In the resulting book, the lives of two generations bound by violence and trauma are explored with disarming clarity and directness.

Heine often photographs the mother-and-child pairs in or around the location where the rape took place – in farmland, on roadsides, in churches. In their poses we may discern something of their relationships. Some hold hands, or embrace, and appear at ease in each other’s company. Others, like the mother and daughter in this photograph taken outside the capital, Kigali, maintain a distance, one turning away from the other as though separated by an insurmountable barrier.

“All these Rwandan children have one thing in common: they were never wanted, were often only reluctantly accepted, sometimes loved, in a patriarchal society that sees them not as victims but as children of murderers,” says Heine.

In the aftermath of the genocide, many of the abused women were unable to find partners and lived in precarious situations, marginalised by society and struggling to accept their children. The therapeutic care provided by organisations such as Solace Ministries, which supported the Rwandan Daughters project, has helped a number of the mothers and children reconcile and move forward – but, as Heine’s powerful testimony suggests, some of the wounds inflicted 25 years ago may never fully be healed.

Rwandan Daughters by Olaf Heine is published by Hatje Cantz (£55)