Rhodesian bombers struck a black nationalist guerrilla base deep inside Angola today, extending the Rhodesian conflict to four states stretching across southern Africa.

The bombers "successfully" attacked a "very large" base of Rhodesian nationalist leader Joshua Nkomo's Zimbabwe African Peoples' Revolutionary Army near the Angolan town of Luso, about 180 miles inside Angola, a short communique from Rhodesian military authorities in Salisbury said. It added that all the planes returned safely.

The Angolan military command later acknowledged the raid, condemning what it called Rhodesia's criminal aggression in the bombing, news services reported.

An Angolan communique said the attack caused casualties and damage which were still to be established.

["Angola will continue to give unconditional support to the Zimbabwe freedom fighters until the final defeat of the hateful regime of (Rhodesian Prime Minister) Ian Smith," the statement added.]

It is the first time Rhodesia has hit so far afield in its six-year-old guerrilla war that has now claimed more than 10,000 lives. Rhodesia's aging British-made Canberra jet bombers had to fly 650 miles from air bases in western Rhodesla, across Zambia and into Angola to strike at the guerrilla base.

The twin-engined Canberras, modified for counterinsurgency use by the Rhodesians, have a range of up to 3,000 miles. The planes took off this morning from Wankie air base, according to informed sources.

This far-reaching air attaack not only escalates the Rhodesian conflict but raises the possibility of direct retailation by the estimated 20,000 Cuban troops and 2,000 East German and Soviet military advisers stationed in Angola. They support the military defenses of the Marxist government there as well train Nkomo's forces.l

The raid is also likely tolfuel suspicions of neighboring black leaders such as Zambian President Kenneth Kaunda that the white-led Rhodesian biracial government would welcome such communist intervention so that the United States and its Western allies would come under pressure to help the beleaguered wsalisbury government.

Another result of the raid may be to dampen last-ditch efforts to bring the warring Rhodesian parties to the conference table. There are signs of such an initiative involving the U.S. and South African governments.

The strike on Angolan territory also poses a wider threat to the whole security situation in southern Africa because it deals a blow to a Western-initiated, U.N. effort to end another guerrilla was in Namibia, which borders on Angola to the south.

The success of that peace effort depends greatly on cooperation by Angola, which also gives sanctuary to a Namibian nationalist guerrilla group.

U.S. and other Western diplomats have been trying to persuade the Angolan government of President Agostinho Neto to cut back the number of Cuban troops there. Neto has privately told U.S. officials that his government would welcome an opportunity to reduce the Cuban military presence in Angola.The Rhodesian stike is likely to increase the Neto government's insecurity and make it more dependent on its communist allies.

This was the fourth Rholdesian air raid in 11 days on the guerrilla camps in neighboring countries. The forces hit twice at Nkomo bases in Zmbia, the latest attack coming Friday on a base about 20 miles from the capital, Lusaka. Rhodesian planes also struct last week at Mugabe's positions in Mozambique.

Rhodesian military authoritiles described the bombed guerrilla camp as the "main training base" for %nkomo's guerrillas in Angola. It is belived to be at Vila de Boma, southeast of Luso, one of the main stops on Angola's Benguela railroad. Many of Nkomo's guerrillas received training from Cuban instructors at camps in Angola and move to camps in Zambia before they go into Rhodesia.

A Rhodesian military spokesman described the operation as "merely routine" and "part of our ongoing defense position," implying that the raid was in return for the shooting down of a Rhodesian civilian airliner two weeks ago that left 59 returning vacationers dead. The plane was shot down by Nkomko's guerrillas with a Sovier-maee heat-seeking missile. It was the second civilian plane downed by Nkomo's forces in the past six months.

The raid appears to be part of a more vigorous offensive posture assumed by the Rhodesian military as elections for a black-majority rule government approach. Both Nkomo and another black Rhodesilan guerrilla leader, Robert Mugabe, based in Mozambique, have threatened to disrupt the April elections because they say they will perpetuate white-minority rule under the guise of a black-majority government in the former British colony.

The two guerrilla leaders are gbelieved to have 10,000 men operating inside Rhodesia and up to 20,000 more ready to come in.