The 1991 Sovereign National Conference (CNS) was a sign of the increasing coherence of the anti-Mobutu forces and came as the Congolese Banyarwanda were in a state of heightened tension. Following the beginning of the Rwandan Civil War in 1990, many young Tutsi men in Kivu decided to cross the border to join the Tutsi-dominated rebel Rwandan Patriotic Front (RPF) in its fight against the Hutu-dominated Rwandan government. In response, the Mobutu government implemented Mission d'Identification de Zaïrois au Kivu to identify non-Zairean Banyarwanda, using the end of the Berlin Conference as the division point. Many Banyarwanda whose families had come as colonial labourers were classified as aliens, resulting in yet more youth joining the RPF. The overall effect of the CNS was to strengthen the tendency of "indigenous" Congolese to differentiate between Tutsi from Hutu, and lump together all Tutsi Banyarwanda as "Banyamulenge". It also underlined the fragility of their political position to the Banyamulenge. Within the Banyarwanda in the Kivus, the Hutu began defining themselves as "indigenous" in comparison to the Tutsis, who were increasingly seen as owing their allegiance to the foreign groups.