During the latter part of the 1960s, military tactical reforms instituted by Gen. Spínola began to improve Portuguese counterinsurgency operations in Guinea. Naval amphibious operations were instituted to overcome some of the mobility problems inherent in the underdeveloped and marshy areas of the territory, using "Destacamentos de Fuzileiros Especiais (DFE)" (special marine assault detachments) as strike forces. The "Fuzileiros Especiais" were lightly equipped with folding-stock m/961 (G3) rifles, 37mm rocket launchers, and light machine guns such as the Heckler & Koch HK21 to enhance their mobility in the difficult, swampy terrain.