South Africa, underscoring its military superiority over its black-ruled neighbors, today staged commando raids in Zimbabwe and Botswana and a combined ground and air strike in Zambia on sites allegedly used by the African National Congress, the main black resistance movement.

Military officials in Pretoria said the raiders hit at "operational centers" and "terrorist transit facilities" in the three countries used by the ANC as staging posts for insurgent attacks inside South Africa. The officials said all of the raids had been "successfully completed," reported Washington Post special correspondent Allister Sparks from Johannesburg. Two persons were reported killed.

The leaders of all three nations sharply criticized the raids. Zimbabwean Prime Minister Robert Mugabe termed the attacks "barbarous . . . cowardly and unprovoked."

The attacks were viewed as a blow to U.S. policy in southern Africa, which has attempted to reduce cross-border violence. Washington expressed "outrage" at the raids and lodged a formal protest with the South African government.

The military offensive was also seen as perhaps fatally damaging a special Commonwealth group's attempts at negotiating an end to violence between ANC guerrillas and Pretoria.

Officials in Zambia said the attack there, a combined air and ground operation that marked South Africa's first raid near the Zambian capital of Lusaka, struck a United Nations refugee camp 10 miles southwest of Lusaka that had no connection with the ANC. In Botswana, the raiders hit a housing complex just outside Gaborone, the capital, that Botswana officials said had no link to the exiled guerrilla group.

The raid at two sites in the Zimbabwean capital here, an ANC office downtown and an apparently deserted house in a middle-class northeastern suburb, marked the first time South Africa has openly attacked this country, the region's most militarily powerful and economically stable black-ruled nation.

In London, the British Foreign Office summoned the South African charge d'affaires to give an "urgent explanation" of the raids as Foreign Minister Geoffrey Howe denounced what he called "a plain violation of the sovereignty of three fellow Commonwealth countries."

The raids come at a time when violence continues to escalate in the black townships in South Africa, and there are signs of an increasing right-wing backlash among the government's white Afrikaner supporters. The attacks followed by two days the discovery by South African police of a large cache of dynamite, plastic explosives and rocket-propelled grenades in a field in Krugersdorp, a Johannesburg suburb.

ANC spokesman Tom Sebina, speaking by telephone from the organization's headquarters in Lusaka, Zambia, told reporters that no ANC members were killed or injured in the attacks.

Casualties in the three countries were reported as light, with two deaths and about 15 injuries. But the raids are certain to raise the level of tension in the region, whose black leaders contend Pretoria is making them scapegoats for growing black unrest inside South Africa.

Leaders of all three black-ruled nations say they do not allow the ANC to use their territory to plan or conduct operations against South Africa. But officials in Pretoria contend the states serve as conduits for arms and ANC operatives.

"It is obvious that Russian mines and weaponry can be brought into South Africa by one route only, namely our neighboring states," said Lt. Gen. A.J. Liebenberg, chief of the South African Army, in a statement today.

Zimbabwe's Mugabe said South Africa had "adopted state terrorism as a policy" and predicted the result would be "a dangerous security situation in the region because the victims will have to defend ourselves."

Mugabe and Zambian President Kenneth Kaunda, who each held press conferences, called for comprehensive and mandatory economic sanctions against Pretoria.

The series of attacks began in Harare, where commandos struck two targets simultaneously shortly after midnight.

At the downtown building, which housed the ANC's Zimbabwe headquarters as well as a cafe and hairdressing salon, police said two men apparently placed a ladder at the front of the two-story building, climbed up to the second floor, broke a window and shoved explosives inside, while another briefly took hostage a private security guard stationed at a building across the street.

Three explosions smashed the floor and roof of the office and injured another security guard who was reportedly sleeping inside the building. The attack took place only half a block from the city's main police station.

The raiders left behind leaflets addressed to "the people of Zimbabwe" stating that the attack was aimed only at "ANC gangsters" who "murder innocent women and children" inside South Africa. The leaflets, which had a South African Defense Force emblem on their back, accused Zimbabwe of assisting the ANC and concluded, "Self-defense is not only our right, it is our duty."

Similar leaflets were dropped in Botswana.

At the suburban house, which reportedly is owned by the ANC, neighbors said they heard about 10 minutes of machine-gun fire followed by two or possibly three explosions.

Mugabe said the ANC house was unoccupied at the time of the raid. An ANC member told reporters the house had been vacated earlier in the evening after the organization received a warning from police that an attack might be coming. All that was left standing was an outside wall next to the driveway. The rest was a pile of rubble.

Mugabe said that four "suspects" had been arrested in "follow up operations" and that an unspecified number of vehicles, explosives and communications equipment had been seized. He refused to comment on how the raiders had entered Harare.

Botswana was the next target. Between eight and 12 helicopters struck a small, privately owned residential complex called Mogoditshane, about three miles outside of Gaborone, at about 6 a.m., according to Sam Moribame, a Botswana Ministry of Information spokesman, and witnesses. The city is just a few miles from the South African border and was hit last June by commandos in a similar attack.

Commandos leaped from the helicopters firing indiscriminately, witnesses said. One Botswana citizen was killed, Moribame said. He added that the Botswana government was not aware of any ANC refugees living in the area.

According to Moribame, members of the Botswana Defense Force fired on the helicopters with antiaircraft weapons, forcing them to withdraw. One Botswana soldier was among the wounded.

President Quett Masire's government issued a statement tonight describing the attack as "a naked act of aggression against our country and the wanton murder of an innocent civilian and maiming of others."

The Zambian attack began shortly before 9 a.m. when two Land Rovers painted blue, which made them resemble Zambian police vehicles, drove up to the refugee camp at Makeni and opened fire with small arms, according to Information Minister Milimo Punabantu. Refugees began pouring out of the camp's buildings, he said, and seconds later, two airplanes swept in low, strafed the camp and dropped fragmentation bombs.

A Namibian refugee was killed and about 10 other persons were wounded, including a child of 2 and another of 5, both Angolans, Punabantu said.

A United Nations representative, speaking to reporters who toured the site today, said the camp housed about 80 refugees from Angola, Namibia and South Africa. None, he said, were ANC members.

The aircraft almost certainly came from the Caprivi Strip, an arm of South African-controlled Namibia that is only about 20 minutes' flying time from Lusaka. South Africa has an airfield with Sabre and Impala jets based there. The Land Rovers could likewise have driven from the strip through southwestern Zambia.

In South Africa, this was one of the bloodiest days in several months of racial unrest, with 26 reported deaths in more than 50 incidents of violence in various parts of the country over the past 24 hours. Twelve of the deaths resulted from what was officially described as "faction fighting" in the black "homeland" of KwaZulu, the cause of which was not immediately known.

In Johannesburg, the Supreme Court today sentenced a Belgian linguist, Helene Passtoors, 44, to 10 years in prison for treason for allegedly supporting the ANC's activities.