Between April and July 1994, over 1 million Rwandan people, mainly Tutsi and some Hutu in the opposition, were killed by the genocidal regime. So many people were involved in the killing. Those who planned and organised the genocide include the late President Major General Juvenal Habyarimana, who was killed by his own entourage, the Presidential Guard, the National Gendarmerie, the Rwanda Government Forces (Army), the MRND-CDR militia (Interahamwe), local officials, and some in the general Hutu population.

Preparation to carry out genocide by these groups involved the training of the militia, the arming of both the militia and some sections of the population, the establishment and widespread use of a hate radio called Radio Television Libre de Mille Collines (RTLM), and the distribution of lists of those who were to be targeted. Repeatedly, these groups prevented the establishment of the Arusha Peace Accords.

When genocide began, the United Nations had a peace-keeping force - the United Nations Assistance Mission for Rwanda (UNAMIR) - in Rwanda of about 2500 troops. The first reaction of the United Nations, and indeed of the other nations that had their own nationals in Rwanda, was to withdraw their troops and their nationals respectively. In the circumstances the RPF had to fight again in order to stop the genocide.