Logiest and Hutu leader Grégoire Kayibanda declared the country an autonomous republic in 1961 and it became independent in 1962. More than 336,000 Tutsi left Rwanda by 1964 to escape the Hutu purges, mostly to the neighbouring countries of Burundi, Uganda, Tanzania and Zaire. Many of the Tutsi exiles lived as refugees in their host countries, and sought to return to Rwanda. Some supported the new Rwandan Government, but others formed armed groups and launched attacks on Rwanda, the largest of which advanced close to Kigali in 1963. These groups were known in Kinyarwanda as the "inyenzi" (cockroaches). Historians do not know the origin of this termit is possible the rebels coined it themselves, the name reflecting that they generally attacked at night. The "inyenzi" label resurfaced in the 1990s as a highly derogatory term for the Tutsi, used by Hutu hardliners to dehumanise them. The "inyenzi" attacks of the 1960s were poorly equipped and organised and the government defeated them. The last significant attack was made in desperation from Burundi in December 1963 but failed due to bad planning and lack of equipment. The government responded to this attack with the slaughter of an estimated 10,000 Tutsi within Rwanda.