The mainly Tutsi rebel force then invaded from Uganda, taking over the country and eventually halting the genocide. Fearing the worst from the new invaders, about two million Hutus fled the country heading to Goma, a town in neighbouring Congo where makeshift camps were set up in appalling sanitary conditions. Thousands died from diarrhoea and disease.
Meanwhile, inside the country hundreds of thousands of others were displaced from their homes.
On one road we were asked to give a young boy a lift. He could barely walk. One foot dragged badly behind him from the effects of polio.
He had been left by the side of the road by his mother who was also carrying his much younger sister. She couldn't carry them both and had decided to leave her son behind. I can't imagine the agony of her decision.
Sitting in the back seat, he quickly ate the biscuits we gave him and then carefully put a few more in his pants pocket, clearly saving them for later.
He told us that he had fled with others in his village to the Congo border, but the conditions there were so bad, his mother had decided to turn back. She had become exhausted when she reached the point where we found him. He didn't say how he felt being the one left behind.
We left him on the side of the road with a few neighbours who knew his village. It was a few kilometres down a dirt road but was rumoured to be mined. We decided not to risk it.
I won't forget that small boy's courage.
No older than 10 or 11, there were no tears, just a determination to find his mother and get home. His story was just one of the thousands of children who became victims of that time.
Reuniting separated children became the centrepiece of our work. We established a base, trained teams of Rwandans to visit houses and refuge centres to locate separated kids. Polaroids were taken, a comprehensive database set up and the process of searching for family members began.
By the time the programme wrapped up, long after I'd left, more than 40,000 children had been reunited with family members or guardians. Very often parents were dead, but relatives were commonly found and children were able to join a family.
This week the BBC remembered the 20th anniversary of the genocide. It released a photo essay that shows the work done by hundreds of Save the Children staff. It included those early photos of lost and bewildered children. But most touchingly, it also captured on film the sheer joy of the moment when parents and children were reunited. -
Rwanda remembered those unforgettable events 20 years ago in ceremonies across the country.
It is still small, overcrowded and poor, but it has undergone a healing process and development that has brought a sense of hope that the future might be better.
David Shearer is a Labour MP and former UN worker.