With decolonization complete, African leaders are turning to conflicts within their own countries that have killed millions of people, maimed countless more and created 5 million refugees. Those internal wars, some decades old, have been largely ignored by the Organization of African Unity, which devoted itself to supporting guerrilla movements in South Africa and colonies ruled by Europeans. Civil wars were considered beyond the bounds of the OAU, whose charter forbade meddling in the internal affairs of member states. Last month, a change began. For the first time since its birth in 1963, the organization declared that ballots should determine the future of the continent's 550 million people, not force of arms. It did not change the charter, but clearly shifted emphasis. ``The issue of restoring peace and stability to African countries and of dismantling the apartheid system was the dominant theme of discussion during the 26th OAU summit,'' the English-language daily Ethiopian Herald said in an editorial. The paper is published in Addis Ababa, headquarters of the OAU. In African eyes, the continent became free of colonies when Namibia gained independence from South Africa in March. Africans viewed Namibia, which South Africa governmed under a U.N. mandate withdrawn in 1966, as a colony of the white-ruled country. The OAU and United Nations have long recognized South Africa as an independent nation, but have tried to end the apartheid racial policy that maintains supremacy for 5 million whites over 28 million blacks. In previous years, the OAU has committed itself to financing guerrilla armies in areas ranging from Cape Verde, when it was a Portuguese colony, to the British territory of Rhodesia, now black-ruled Zimbabwe. It ended the June summit with the usual condemnation of apartheid, but for the first time omitted mention of continuing to support guerrilla-backed movements like the African National Congress or Pan-Africanist Congress. Instead, Africa's leaders committed themselves to increasing democracy within their own countries and finding peaceful solutions to civil wars in progress from the Western Sahara in the far northwest to Mozambique in the southeast. Here is a look at the long-running wars: ANGOLA _ Portugal, the colonial power, pulled out of this agriculturally rich West African territory in 1975, leaving three anti-colonial guerrilla armies to fight for the spoils. The Popular Movement for the Liberation of Angola won. Since then, the Marxist government has battled Jonas Savimbi's National Union for the Total Independence of Angola, which has U.S. support. Zaire is mediating peace talks. CHAD _ This landlocked desert nation in north central Africa, independent from France since 1960, has been torn by rebellions and three civil wars. Virtually all involved meddling and military incursions by Chad's northern neighbor, Libya, with which it has a border dispute. President Hissen Habre's army scored a major victory over the Libyans in 1987, but skirmishing continues between government forces and Libyan-backed rebels. ETHIOPIA _ For 29 years, Africa's longest civil war has raged in northernmost Eritrea Province, where rebels of the Eritrean People's Liberation Front control virtually all the countryside and the port of Massawa, one of Ethiopia's two Red Sea harbors. The Eritreans, loosely allied with the Tigre People's Liberation Front in neighboring Tigre province, want independence for Eritrea, a former Italian colony federated with Ethiopia in 1952. The Tigreans want to overthrow the central government of President Mengistu Haile Mariam. The two conflicts and the famines they spawned have claimed more than 1 million lives. MOZAMBIQUE _ After Portugal granted independence in 1975, a rebel army called the Mozambique National Resistance, known as Renamo, was organized within Mozambique by the white military of neighboring Rhodesia. Mozambique was the main springboard for incursions by guerrillas bent on toppling Rhodesia's white-minority government. White-ruled South Africa took over Renamo after Rhodesia became Zimbabwe in 1980, but now says it has ended support of the guerrillas. Hundreds of thousands of people have died and other hundreds of thousands have fled Mozambique. Preliminary peace talks began last year, but no real progress is evident. SOMALIA _ Since 1969, when he took power in a military coup, President Mohammed Siad Barre has ruled this Horn of Africa nation with what human rights groups describe as nearly unmatched brutality. Insurgents in the north have fought his regime for a decade and new rebel organizations sprang up in the south last year. The president has promised a referendum on a new constitution later this year and multiparty elections early in 1991. SUDAN _ For seven years, southern rebels who are mainly Christian or animist have been fighting for autonomy from the Moslem-dominated central government in Khartoum. Former President Jimmy Carter arranged peace talks last year that failed to settle the conflict. As in Ethiopia, the fighting has led to periodic famine and the loss of hundreds of thousands of lives. WESTERN SAHARA _ Morocco and the Polisario Front, a Marxist group, have been at war since 1977 over the desolate Western Sahara. Spain as the colonial power, granted the region to Morocco and Mauritania in 1975, but Mauritania later abandoned its claim. The Morocco-Polisario conflict has been largely at stalemate in recent years.