The Rwanda genocide was the systematic killing of hundreds of thousands of people belonging to the Tutsi minority ethnic group by the majority Hutus. Most of the killing occurred within a span of 100 days in the summer of 1994. It was carried out by two Hutu extremist military groups. At least 500,000 people were immediately killed, and as many as one million people lost their lives by the end of the massacre. The genocide had its roots in the Rwanda Civil War, which pitted the majority Hutus against the Uganda-supported Tutsi minority.