Mozambique, Guinea and Angola in the close-support role. The first 40 G.91 were purchased second-hand from the Luftwaffe, aircraft that had been produced for Greece and which differed from the rest of the Luftwaffe G.91s enough to create maintenance problems. The aircraft replaced the Portuguese F-86 Sabre. The Portuguese Navy (particularly the Marines, known as Fuzileiros) made extensive use of patrol boats, landing craft, and Zodiac inflatable boats. They were employed especially in Guinea, but also in the Congo River (and other smaller rivers) in Angola and in the Zambezi (and other rivers) in Mozambique. Equipped with standard or collapsible-stock m/961 rifles, grenades, and other gear, they used small boats or patrol craft to infiltrate guerrilla positions. In an effort to intercept infiltrators, the Fuzileiros even manned small patrol craft on Lake Malawi. The Navy also used Portuguese civilian cruisers as troop transports, and drafted Portuguese Merchant Navy personnel to man ships carrying troops and material and into the Marines. There were also many Portuguese irregular forces in the Overseas War such as the Flechas and others, as mentioned above. Native black warriors were employed in Africa by the Portuguese colonial rulers since the 16th century. Portugal had employed regular native troops (companhias indigenas) in its colonial army since the early 19th century. After 1961, with the beginning of the colonial wars in its overseas territories, Portugal began to incorporate black Portuguese Africans into integrated units as part of the war effort in Angola, Portuguese Guinea, and Mozambique, based on concepts of multi-racialism and preservation of the empire. African participation on the Portuguese side of the conflict varied from marginal roles as laborers and informers to participation in highly trained operational combat units like the Flechas. As the war progressed, use of African counterinsurgency troops increased; on the eve of the military coup of 25 April 1974, black ethnic Africans accounted for more than 50 percent of Portuguese forces fighting the war. From 1961 to the end of the Colonial War, the paratrooper nurses nicknamed Marias, were women who served the Portuguese armed forces being deployed in Portuguese Africa's dangerous guerrilla-infiltrated combat zones to perform rescue operations. enfermeiras , Green beret, sapo.pt Throughout the war period Portugal had to deal with increasing dissent, arms embargoes and other punitive sanctions imposed by most of the international community. The later included UN-sponsored sanctions, Non-Aligned Movement-led defamation, and myriad boycotts and protests performed