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 ordered all Mau Mau suspects to be screened. Of the scores of screening camps which sprang up, only fifteen were officially sanctioned by the colonial government. Larger detention camps were divided into compounds. The screening centres were staffed by settlers who had been appointed temporary district-officers by Baring. Thomas Askwith, the official tasked with designing the British 'detention and rehabilitation' programme during the summer and autumn of 1953, termed his system the "Pipeline". The British did not initially conceive of rehabilitating Mau Mau suspects through brute force and other ill-treatment—Askwith's final plan, submitted to Baring in October 1953, was intended