The Hutu are the largest of the three ethnic groups in Burundi and Rwanda . The United States Central Intelligence Agency says 84 % of Rwandans and 85 % of Burundians are Hutu . The Hutu are the largest of the three ethnic groups in Burundi and Rwanda ; according to the United States Central Intelligence Agency , 84 % of Rwandans and 85 % of Burundians are Hutu , although other sources have found statistics that differ by several percent .