United Nations peacekeepers have found over 100 bodies in three mass graves in the east of Democratic Republic of Congo, the country's U.N. mission said on Saturday. A patrol of South African soldiers discovered the graves on Friday near the village of Maboya in troubled North Kivu province. A U.N. spokesman told Reuters a preliminary excavation of the site indicated they had not been dug recently. "Apparently they were graves dating back to the 1990s, but it's difficult to know accurately," U.N. mission spokesman Kemal Saiki said. "The first one they excavated contained 100 bodies. The second was seven, and the third one they couldn't estimate." Saiki said Congolese authorities were planning to investigate the site. The central African nation's eastern borderlands have long been gripped by a conflict that grew out of neighboring Rwanda's 1994 genocide, in which Hutu extremists slaughtered some 800,000 Tutsis and moderate Hutus.