It is members of the military who are on the ground, not armed groups from outside. It seems that the population have identified soldiers in these military groups who do not speak the local language, whether Lingala, French or Tshiluba.
It is clear that many Congolese law enforcement personnel have understood that the orders from their superiors are not fair, that they do not represent justice. These killings are for the most part being perpetrated by Rwandan and Ugandan military members wearing the uniforms of Congolese police forces.