UN peacekeepers in Congo thought they had a confrontation with Rwandan troops (who were looking for Hutu rebels.) But what they apparently ran into were Congolese Tutsi rebels (backed by Tutsi dominated Rwanda). The Tutsi tribes in Congo are still supported by Rwanda, as a force that can fight the Hutu rebels in Congo. The UN estimates that there are still some 8,000 Hutu rebels in Congo, and since 2002 some 11,000 have been sent back to Rwanda.
