The ARA began its military actions in October 1970, keeping them up until August 1972. The major actions were the attack on the Tancos air base that destroyed several helicopters on March 8, 1971, and the attack on the NATO headquarters at Oeiras in October of the same year. The BR, on its side, began armed actions on 7 November 1971, with the sabotage of the NATO base at Pinhal de Armeiro, the last action being carried out 9 April 1974, against the Niassa ship which was preparing to leave Lisboa with troops to be deployed in Portuguese Guinea. The BR acted even in the colonies, placing a bomb in the Military Command of Bissau on 22 February 1974.