Operation Anvil (Mau Mau Uprising) the reserves. The "Grey" grade was made up of prisoners believed to be passive Mau Mau sympatherisers though for whom strong evidence suggesting their true loyalties was lacking. The last category, "Black", was reserved for detainees identified by the hooded informers or the Special Branch of the Kenya Police as potentially violent insurgents or terrorists. A few may have been prosecuted by the government, but most were funneled through the "Pipeline", a system of work camps, decreasing in brutality until an individual was "re-educated" and deemed safe to release on a native reserve. Operation Anvil (Mau Mau Uprising) Operation Anvil
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