Impuzamugambi
The Impuzamugambi was made of young people from an ethnic group called the Hutus.  A similar militia, the Interahamwe, was also made of young Hutus.  Together, these two militias killed tens of thousands of Tutsis, members of another ethnic group, in the Rwandan genocide.  They also killed some Hutus who did not agree with the pro-Hutu government.