Kigali was not directly affected during the first three years of the 1990–1994 Rwandan Civil War, although the rebel Rwandan Patriotic Front (RPF) did come close to attacking the city in February 1993. In December of the same year, following the signing of the Arusha Accords, a United Nations peacekeeping force was established in the city, and the RPF were granted use of a building in the city for their diplomats and soldiers. In April 1994 President Habyarimana was assassinated when his plane was shot down near Kigali International Airport. Burundian president Cyprien Ntaryamira was also killed in the attack. This was the catalyst for the Rwandan genocide, in which 500,000–800,000 Tutsi and politically moderate Hutu were killed in well-planned attacks on the orders of the interim government. Opposition politicians based in Kigali were killed on the first day of the genocide, and the city then became the setting for fierce fighting between the army and the RPF including at the latter's base. The RPF began attacking from the north of the country, and gradually took control of most of Rwanda between April and June. After encircling Kigali and cutting off its supply routes, they began fighting for the city itself in mid-June. The government forces had superior manpower and weapons but the RPF fought tactically, and were able to exploit the fact that the government forces were concentrating on the genocide rather than the fight for Kigali. The RPF took control of Kigali on 4 July, a date now commemorated as Liberation Day, a Rwandan national holiday.