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
Operation Anvil (Mau Mau Uprising) In the weeks preceding the operation rumors circulated among the African population that Nairobi was due to be subjected to a security sweep. Some insurgents moved to the outskirts of the city and were thus outside the cordoned area. On 04:30 on 24 April British forces initiated Operation Anvil, sealing off every road and track leading in or out of Nairobi. Government forces then surrounded locations which were home to substantial Kikuyu populations in the city such as Makongeni, Bahati, Kariokor, Ziwani, and Pumwani, thus preventing any Mau Mau from escaping. Informers disguised with hoods identified suspected rebels to the