 The official first assignment of Brimob Rangers was the Fourth Military Operations Movement in South Sumatra, West Sumatra and North Sumatra (in response to the Permesta rebellion of 1958).In this GOM IV Brimob Rangers troops became part of the Bangka Belitung Infantry Battalion led by Lieutenant Colonel (Inf) Dani Effendi.Rangers were tasked to capture the remains of the PRRI prison in Sumatra's forest led by Major Malik, which was then under rebel hands.