Portugal commenced "Operação Mar Verde" or "Operation Green Sea" on 22 November 1970 in an attempt to overthrow Ahmed Sékou Touré, the leader of the Guinea-Conakry and staunch PAIGC ally, to capture the leader of the PAIGC, Amílcar Cabral, and to cut off supply lines to PAIGC insurgents. The operation involved a daring raid on Conakry, a PAIGC safe haven, in which 400 Portuguese "Fuzileiros" (amphibious assault troops) attacked the city. The attempted coup d'état failed, though the Portuguese managed to destroy several PAIGC ships and free hundreds of Portuguese prisoners of war (POWs) at several large POW camps. One immediate result of "Operation Green Sea" was an escalation in the conflict, with countries such as Algeria and Nigeria now offering support to the PAIGC as well as the Soviet Union, which sent warships to the region (known by NATO as the "West Africa Patrol") in a show of force calculated to deter future Portuguese amphibious attacks on the territory of the Guinea-Conakry. The United Nations passed several resolutions condemning cross-border attacks of the Portuguese military against the PAIGC guerrilla bases in both neighboring Guinea-Conakry and Senegal, like the United Nations Security Council Resolution 290, United Nations Security Council Resolution 294 and the United Nations Security Council Resolution 295.