-LRB- CNN -RRB- -- Rwandan troops have crossed into the Democratic Republic of Congo to prepare for a joint operation with Congolese forces against a Hutu militia , the United Nations said . At least 800,000 people are thought to have died during 100 days of violence in Rwanda in 1994 . `` We can tell you there are Rwandan soldiers here , but I can not confirm the numbers , '' said Madnodje Mounoubai , spokesman for the U.N. mission in the Democratic Republic of Congo . The Rwandans will team up `` with the Congolese forces , '' he said Wednesday . `` The Rwandan forces are in a meeting with Congolese forces and the understanding is that in the meeting they are preparing a joint operation against the FDLR , '' or the Democratic Liberation Forces of Rwanda . The Rwanda News Agency reported that Rwanda has dispatched 1,917 soldiers . Rwanda and Congo traditionally have been on different sides of the conflict in eastern Congo . The struggle pits ethnic Tutsis , supported by Rwanda , against ethnic Hutu , backed by Congo . The conflict is effectively an extension of the Rwandan genocide dating back to the early 1990s , when hundreds of thousands of Rwandans were killed in ethnic battles between minority Tutsi and majority Hutu . According to a statement issued last week by the Rwandan government , the joint military operation is aimed at driving out the FDLR and former members of the Interhamwe militia , `` remnants of those who spearheaded the 1994 genocide against Tutsis . '' Michael Arunga , a Kenya-based spokesman for the World Vision aid organization , said his colleagues in Goma -- a city in eastern Congo -- told him that Rwandan troops arrived Tuesday morning in the village of Ishsha , outside of Goma . Arunga said he had no knowledge of Rwandan troops being in Congo before . A U.N. statement said the FDLR has been involved in clashes since late August mainly in North Kivu , `` where the national army , the mainly Tutsi militia -- known as the CNDP -- and other rebel groups ... have fought in shifting alliances , uprooting around 250,000 civilians on top of the 800,000 already displaced by violence in recent years . '' See photos from Mia Farrow 's trip to the Democratic Republic of Congo '' A report by a U.N. Security Council panel last month said Rwanda and Congo were fighting a brutal proxy war for territory and precious natural resources in eastern Congo , and all parties involved in the conflict were using execution , rape and child soldiers as tools of war . The report , filed by a panel of U.N. experts , `` found evidence that Rwandan authorities have sent officers and units of the Rwanda Defense Forces '' into Congo in support of Congo rebel leader Laurent Nkunda 's fighters . CNN 's Carolina Sanchez contributed to this report .