Mau Mau Uprising attempt to eliminate Mau Mau's presence within Nairobi in one fell swoop. 25,000 members of British security forces under the control of General George Erskine were deployed as Nairobi was sealed off and underwent a sector-by-sector purge. All native Kenyans were taken to temporary barbed-wire enclosures, whereafter those who were not Kikuyu, Embu or Meru were released; those who were remained in detention for screening. Whilst the operation itself was conducted by Europeans, most suspected members of Mau Mau were picked out of groups of the Kikuyu-Embu-Meru detainees by a native Kenyan informer. Male suspects were then taken off for
Mau Mau Uprising as "a complete blueprint for winning the war against Mau Mau using socioeconomic and civic reform." What developed, however, has been described as a British gulag. The Pipeline operated a white-grey-black classification system: 'whites' were cooperative detainees, and were repatriated back to the reserves; 'greys' had been oathed but were reasonably compliant, and were moved down the Pipeline to works camps in their local districts before release; and 'blacks' were the so-called 'hard core' of Mau Mau. These were moved up the Pipeline to special detention camps. Thus a detainee's position in Pipeline was a straightforward reflection of how cooperative