Rhodesian jet fighters have begun attacking nationalist guerrilla camps in southern Zambia, in what a Salisbury military communique said was an effort to block a large infiltration of guerrilla forces into Rhodesia.

The brief statement said the raids, of unspecified size and duration, took place early this morning in the area of Livingstone, a few miles from Victoria Falls, and that "all aircraft have returned safely to base."

It said Rhodesian intelligence reports indicated that guerrillas of the Zambia-based Zimbabwe African People's Union (ZAPU) under Joshua Nkomo were grouping there and preparing to infiltrate into Rhodesia.

"These holding camps were situated outside the built-up areas of Livingstone and only these ZIPRA camps were attacked," the statement added. ZIPRA is the acronym for Nkomo's guerrilla army.

Diplomatic and nationalist sources here, however, have been reporting Rhodesian air and ground attacks against the guerrilla camps since Wednesday. The number of casualties is not known so far.

Neither ZAPU, which has its headquarters here, nor the Zambian government has said anything about the raids.

Observers here said many more attacks were likely in coming days and weeks. Zambia has been bracing itself for retaliatory raids from Rhodesian security forces since ZAPU guerrillas shot down a second Air Rhodesia Viscount plane Monday, killing all 59 persons aboard.

Last September, ZAPU brought down another Rhodesian passenger plane, resulting in the death of 48 persons, 10 of them reportedly killed by guerrillas after surviving the crash.

The Rhodesian military communique today did not link the latest publicized raids to any campaign of retaliation for the latest air disaster. Rhodesia's top military comander, Lt. Gen. Peter Walls, said Thursday his forces had no intention of mounting a hasty retaliation but assured Rhodesians the military would take "whatever action is necessary at the right time, at the right place and in the right way."

After ZAPU shot down the first Air Rhodesia plane, the Rhodesian Army and Air Force waited about six weeks before unleashing a series of air and ground attacks on 12 guerrilla and refugee camps here. About 1,000 persons were killed in those raids.

The buildup of ZAPU guerrillas in southern Zambia is thought in Salisbury and here to be related to the April elections in Rhodesia for a black majority government in which whites will continue to exercise considerable power.

The two factions of the Patriotic Front, the guerrilla alliance fighting to overthrow the Rhodesian transitional government, have vowed to prevent the elections from taking place and have been building up their forces inside Rhodesia.

Altogether, there are probably more than 10,000 guerrillas inside Rhodesia now, with thousands more being infiltrated from Mozambique and Zambia. The other wing of the front, under Robert Mugabe, is based in Mozambique.

The Rhodesians have been infiltrating agents into Zambia for some time now on what appear to be scouting missions in preparation for renewed air and ground atacks to offset the guerrilla election offensive.

This past week, one black believed to be a Rhodesian spy was captured walking along the main highway just a few miles east of Lusaka. He was carrying two automatic rifles and a hand grenade. An accomplice escaped into the bush.

In addition, at least one white farmer on the outskirts of Lusaka near the international airport reported to police that he was visited and asked for food by two suspicious looking whites traveling in a battered truck.

Meanwhile, repercussions continue inside Rhodesia following the latest Air Rhodesia crash linked to guerrilla action.

South African Airways has announced that it is suspending flights of jumbo jets to Salisbury and of all its airliners to Victoria Falls and Kariba. The latter, a lakeside resort town, was the departure point for both Air Rhodesia aircraft that crashed after being hit by guerrilla ground-to-air Strella missiles.

The airways said it would add three additional flights between Salisbury and Johannesburg to allow Rhodesians destined for European cities to make connections. But the suspension of the South African Airway flights is bound to add to the growing sense of isolation among whites in Rhodesia and further set back its already dwindling tourist trade.