The Rwandan genocide occurred in 1994 when ethnic Hutu extremists killed an estimated 800,000 Tutsi and moderate Hutu people over a period of 100 days. The genocide stemmed from longstanding ethnic tensions between the Hutu and Tutsi groups that were exacerbated by Belgian colonists who favored the Tutsi minority. On April 6, 1994, the presidents of Rwanda and Burundi were killed when their plane was shot down, triggering a wave of violence by Hutu militias who went from house to house killing thousands of Tutsi civilians each day using machetes, clubs and other basic implements.