Papua province, the location the massacre has seen low-level insurgency since its incorporation into Indonesia. Unlike other parts of the former colony of Dutch East Indies, which was recognized as part of United States of Indonesia following Dutch–Indonesian Round Table Conference of 1949, Western Papua has only been administrated by Indonesia since 1963. At the time of a contentious Act of Free Choice in 1969, the U.S. Ambassador asserted "a decided majority of the Irianese (Papuan) people, and possible 85 to 90%, are in sympathy with the Free Papua cause". Activists who objected to the Indonesian claim of incorporation of Papuan territories into the Republic have formed independence groups including West Papua Liberation Organization and the OPM. The conflict is further fueled by economic disadvantage and poverty of Native Papuans, immigration of other ethnic groups (Transmigration program) and human rights violations by Indonesian forces.