Operation Anvil (Mau Mau Uprising) authorities. Within 48 hours the British had detained 206 known insurgents. In the following weeks over 50,000 Africans were detained and questioned. Nevetheless, numerous leading figures among the rebels managed to escape from Nairobi into the countryside. The operation ended on 26 May. Operation Anvil marked a turning-point in the British campaign against the Mau Mau. The action left the insurgents mostly isolated in the forested mountains of Nyandarwa and Kirinyaga without access to supplies and the assistance of passive supporters. It proved to be the most sophisticated undertaking of the Kenyan Emergency. In the following weeks Mau Mau activity
Mau Mau Uprising relocated. Between 320,000-450,000 of them were moved into concentration camps. Most of the remainder – more than a million – were held in "enclosed villages". Although some were Mau Mau guerrillas, most were victims of collective punishment that colonial authorities imposed on large areas of the country. Hundreds of thousands suffered beatings and sexual assaults during "screenings" intended to extract information about the Mau Mau threat. Later, prisoners suffered even worse mistreatment in an attempt to force them to renounce their allegiance to the insurgency and to obey commands. Significant numbers were murdered. Prisoners were questioned with the help of