Mozambique rebels: do their guns, money come from S. Africa?

''We are in a decisive battle in which the real enemy is South Africa,'' a senior Mozambican government minister says.

South Africa, many top officials here allege, is craftily making it appear as though increasingly bold attacks on towns, power lines, and bridges in this nation's border regions are staged by Mozambican rebels who are ideologically opposed to the country's leftist leaders.

But in fact, these officials say, South Africa is the driving force behind the rebel strikes. The guerrillas, they assert, are but proxies with no political vision - many of them mercenaries - in a South African maneuver to dislodge Mozambique's leftist-leaning government.

South Africa's main weapon in this drive, say high-level military and civilian officials, is the Mozambique National Resistance (MNR), which they describe as a disparate band of guerrillas organized by ex-Portuguese secret police agents and Rhodesian security agents in 1976. This story is corroborated by former Rhodesian Intelligence Chief Ken Flowers, who was intimately associated with the project.

South Africa's ties to the MNR date from its formation, although it was not until late in 1979, when the Rhodesian government was shifting to black control, that South Africa took charge of the group, the officials say.

The South African parental link to the MNR appears to be corroborated in an MNR document captured by the Mozambican Army and seen by the writers of this story. Minutes of a meeting between MNR Supreme Commander Alfonso Dhlakama and Rhodesian and South African security men, quote Mr. Dhlakama as saying, ''You South Africans are like my parents. . . . Everything depends on you.'' Dhlakama is said to have been handpicked to lead the group by the Rhodesians and South Africans.

Over the past few years, with Pretoria's backing, the MNR has intensified its military activity in the southern half of Mozambique, attacking bridges, railroad lines, and communal villages - apparently in an effort to paralyze Mozambique's economy.

South Africa's overriding objective, however, is said by Mozambican officials to be to sabotage the Southern African Development Coordinating Conference, the regional alliance of Mozambique, Zimbabwe, Angola, Swaziland, Lesotho, Botswana, Malawi, Zambia and Tanzania forged to break South Africa's economic domination of the region.

Another captured MNR document, seen by the writers, describes a meeting between Dklakama and Col. Van Nierok of South African security on Oct. 25, 1980, in which Van Nierok ordered the MNR to ''interdict rail traffic (in southern Mozambique), establish bases inside Mozambique adjacent to the South African border, open a new military front in Maputo Province.''

These activities, according to the captured documents, were intended to discourage Zimbabwe from exporting its commodities through Maputo, Mozambique's capital, which was was drawing substantial traffic away from South African ports.

South Africa promised to supply rebels with large amounts of war material in exchange for specific acts of sabotage, according to the documents. The war material included rockets, mortars and small arms, and advisers ''who will not teach but also participate in attacks,'' according to the documents.

Mozambican Army commanders interviewed by the writers indicated that the Army had encountered ''Boers'' in battles against the rebels in central Mozambique. When pressed to explain what they meant, a young officer who fought in the northern province of Manica said that his battalion discovered the bodies of several European soldiers when they overran an MNR base at Chidogo. South African passports and other documents were captured at other MNR bases, he said.

The Mozambican military and civilian officials say South Africa is training MNR forces at military bases in the Transvaal Province bordering Mozambique. They say it is providing supplies and logistical assistance to the guerrillas inside Mozambique.

According to Mozambican field commanders in Manica and Tete provinces, MNR forces are regularly supplied at night. They say the Mozambique government forces lack the communications and air support to prevent such air drops. And the country's long Indian Ocean coastline is ideally suited for delivering armaments by sea.

Western diplomats here estimate the MNR's numbers at about 5,000. Many, if not most, of the rebel recruits seem to be coerced into joining.

A Mozambican woman, Sara Muchalima, says: ''The bandits came to my house and told my parents I had to go with them. My father refused, but they beat him up, tied my hands, and with a gun to my head took me to their base at Garangua.''

Further corroboration comes from John Burleson, a British ecologist held prisoner by the MNR for several months, who reports seeing hundreds of forced recruits kept under armed guard.

But Mozambique has serious economic problems and this, too, is a factor contributing to guerrilla recruitment, observers say. Droughts, failure of the family farming sector, and lack of consumer goods in some areas provide fertile ground for MNR recruitment. The MNR also appears to play on tribal values against the leftist idealogy.

But as quickly as the support builds for the MNR, it fades. Looting and terrorism in the areas in which the MNR is active are alienating the rural population. A growing number of peasants have fled to Zimbabwe.

In Inhambane Province, refugees said the MNR murdered people and stuffed them into wells. Refugees said an MNR band stopped a train on Aug. 9 and raked it with machine-gun fire; 14 persons were reported killed and 50 wounded.

One top Western diplomat, who admitted that he was initially skeptical of such reports about the MNR, now says he finds ''reports of widespread MNR barbarism credible.''