Tutsi which the Hutu then in power killed an estimated 500,000–1,000,000 people, largely of Tutsi origin. Victorious in the aftermath of the genocide, the RPF came to power in July 1994. Tutsis speak Rwanda-Rundi as their native language. It is a member of the Bantu subgroup of the Niger–Congo family. Rwanda-Rundi is subdivided into the Kinyarwanda and Kirundi dialects, which have been standardized as official languages of Burundi and Rwanda. Rwanda-Rundi is also spoken as a mother tongue by the Hutu and Twa. Additionally, many Tutsis speak French, the third official language of Rwanda and Burundi, as a lingua franca. The
Hutu of Rwandan national unity, but has been criticized as an attempt at historical revisionism. Still others suggest that the two groups are related but not identical, and that differences between them were exacerbated by Europeans, or by a gradual, natural split, as those who owned cattle became known as Tutsi and those who did not became Hutu. Mahmood Mamdani states that the Belgian colonial power designated people as Tutsi or Hutu on the basis of cattle ownership, physical measurements and church records. There is an ongoing debate as to whether the Hutu and Tutsi are really separate groups or not;