As explained by the study conducted by the National Commission for the Fight against Genocide (CNLG) on the history of the Genocide committed against the Tutsi in the former Gitarama Prefecture, perpetration of acts of killings and violence against the Tutsi begun in the end of February 1973. The plot of the masterminds of these ignoble actions was to target all the Tutsi, starting from those in schools and different services. Top leaders of the PARMEHUTU party including president Kayibanda Grégoire himself incited their partisans to blaze and destroy the houses of the Tutsi as well as killing them. Acts of killings and violence targeting the Tutsi in 1973 were ignited by the impasse between Rwanda and Burundi.
In the commune of Nyamabuye, killings targeting the Tutsi were perpetrated in the end of February 1973. Uproar in Gitarama started from the Shyogwe secondary school in the night of 26-27 February 1973. In that night, the student from the Shyogwe secondary school killed Murekezi Oswald, a nurse who used to care for them. They burnt his body inside his home, ousted all the Tutsi students and teachers. Other killed Tutsi include Gatsimbanyi, Kavuke, Gaston and Mabuye. They were killed by PARMEHUTU partisans led including Nyirimanzi. The survivors took refuge to the Cyeza Parish.
Acts of violence including the killing and burning of the houses of the Tutsi quickly spread to the remote areas. The houses of the Tutsi were burnt, others destroyed while their properties were looted. Up until March 6, 1973, the number of Tutsi refugees ousted from their properties had hit 5860. Some Tutsi were killed and thrown into the Nyabarongo River.
The killings committed against the Tutsi in the commune of Nyamabuye are shown in the letter dated March2, 1973, which father Michel Rwabigwi, the priest of Cyeza parish, addressed to the Prefect of Gitarama requesting him to order the bourgoumestres of the communes to proceed with the burial of the victims of what his referred to as turbulence.
Father Michel Rwabigwi added that he had by then received refugees amounting to three hundred forty-five (345) and that they were still pouring in. Among the refugees, he noted, 85 were men, 70 women, 24 young boys, 28 young girls while 138 were toddlers.