Hutu as was the person constitutionally entitled to succeed him. This sparked a genocide in Burundi between Hutu political structures and the Tutsi military, in which an estimated 500,000 Burundians died. There were many mass killings of Tutsis and moderate Hutus; these events were deemed genocide by the United Nations International Commission of Inquiry for Burundi. While Tutsi remained in control of Burundi, the conflict resulted in genocide in Rwanda as well. A Tutsi rebel group, the Rwandan Patriotic Front, invaded Rwanda from Uganda, which started a civil war against Rwanda's Hutu government in 1990. A peace agreement was signed, but
Ethnic groups in Burundi declared a presidential republic; however peace did not ensue as a result. Even after 1966, the subsequent dictatorial regimes of Michel Micombero (1966–76), Jean-Baptiste Bagaza (1976–87), and Pierre Buyoya (1987–93) were dominated by Tutsi elites which often consciously marginalized and discriminated against the Hutu majority. The first Hutu to become head of state was Melchior Ndadaye in 1993, although he was assassinated shortly after taking power. Ethnic violence peaked in 1972 when 100,000 people, mainly Hutu, were killed by the Tutsi regime in the Burundian Genocide. Twa have also been targeted, specifically in violence directed against the Tutsi with whom