Rwandan genocide
However, on April 6, 1994, an airplane carrying the Presidents of Rwanda and Burundi was shot down.  Both Presidents were Hutus.  Nobody knows for sure who shot down the plane.  The RPF said the Hutu extremists had shot down the plane themselves, just because they wanted an excuse to start killing people.  The Hutu extremists blamed the Tutsi RPF, and right away, they started killing Tutsis.