Tutsis and Hutus
Tutsis were originally from Ethiopia and they migrated into Rwanda while the Hutus came in from Chad. When the Hutu president of Rwanda was assassinated when his plane was shot down near Kigali the Hutus went into conclusion that it was the Tutsis plan to murder the president even though there was no evidence on who shot down the president. The widespread genocide began by Hutu extremists killing, raping, kidnapping Tutsi rebels and their plan was to make them disappear. All of this took place in Rwanda, Africa. As soon as this genocide ended many Hutus migrated to Eastern of the Congo which is how both groups Tustis and Hutus ended up in the D.R.C.
Sources
http://www.globalresearch.ca/rwandan-war-criminals-defeated-in-congo-but-africom-riding-high/5357189
http://worldwithoutgenocide.org/genocides-and-conflicts/congo
http://worldnews.about.com/od/africa/f/tutsihutu.htm
Image Source
http://www.globalresearch.ca/wp-content/uploads/2013/11/M23Congo.jpg