The Rhodesian defense force yesterday conducted raids on an unspecified number of guerrilla bases in neighboring Mozambique, Rhodesian military headquarters announced in Salisbury.

It is the second time the military authorities have acknowledged a raid on guerrilla bases in neighboring countries since the biracial transitional government of Prime Minister Ian Smith and three black-leaders was formed last March.

On March 6, Rhodesian forces invaded Zambia and killed 42 guerrillas of Joshua Nkomo's Zimbabwe People's Revolutionary Army.

In an unusual move apparently calculated to prevent Mozambican government forces from getting involved in the fighting, the announcement was made while the raids were still in progress, emphasizing that they were directed against the guerrilla forces and not against civilians or Mozambican forces, "with whom there is no quarrel."

The Rhodesian military authorities also appear to be anticipating that their action will draw criticism from the black leaders involved in the Salisbury biracial government. The announcement also noted that the raids "were conducted in support of the interim government of Rhodesia."

Recriminations between white and black members of the transitional government over a failure to wind down the six-year-old guerrilla war have added to a growing list of problems for the experiment in biracial rule which is intended to lead to majority rule by the end of this year.

Yesterday's communique said that "security forces are launching self defense operations against selected terorist bases in Mozambique." No details on how many bases were being attacked, when the operation had begun, or when it would end were given. Observers in Salisbury noted that there was unusually heavy air activity Saturday, and as far as journalists could determine, Rhodesian forces were still in Mozambique late yesterday.

The guerrilla bases in Mozambique are used by the Zimbabwe African National Liberation Army, the military wing of Robert Mugabe's Zimbabwe African National Union (ZANU). Zimbabwe is the nationalist name for Rhodesia.

The last publicly admitted raid into Mozambique took place last December when Rhodesian air and ground forces attacked two major bases more than 60 miles inside the country. Rhodesian authorities claimed they killed more than 1,200 guerrillas in that operation, but Mozambique said many of those killed were civilian refugees.

So far, Rhodesian defense authorities have acknowledged five major operations into Mozambique in the course of their war, as well as two into Botswana and one into Zambia. Zambia allows the guerrilla forces of Nkomo, Mugabe's co-leader in the Patriotic Front guerrilla alliance, to operate from its territory.

Rhodeisan military headquarters also announced yesterday that in the last five days 45 more people have died in the war, which is estimated to have claimed at least 10,000 lives since 1972. The release said 37 of those killed were "terrorists" and one was "a terrorist collaborator." The others were black civilians killed by guerrilla forces, the communique said.

In recent months, two black internal leaders, Bishop Abel Muzorewa and Rev. Ndabaningi Sithole, have blamed the Rhodesian Army, which is 80 percent black but his white officers, for the failure to bring about a cease-fire between the guerrillas and government forces.

Smith has expressed disappointment that Muzorewa and Sithole have not been able to convince the guerrillas to accept an amnesty offer made last May. Both Muzorewa and Sithole are currently traveling outside Rhodesia.

Sithole disputes the leadership of Mugabe in ZANU and in a recent interview claimed he had the allegiance of more than 75 percent of the estimated 5,000 ZANU guerrillas believed to be operating inside Rhodesia.

Despite Sithole's claims, the war has intensified since the biracial government assumed power last March, with the average weekly death toll reaching more than 100.

Prepresentatives of Sithole and Muzorewa who have attempted to meet guerrilla leaders to discuss a cease-fire have been killed by guerrillas. Recent visitors to Salisbury report that guerrillas roam at will in large areas of the countryside and that only two main roads out of Salisbury are safe to travel without military escort.

Despite the bleak situation, yesterday's military communique claimed that "there is clear evidence that the cease-fire exercise is beginning to work within Rhodesia and there is intelligence that there are other groups who are showing every indication of cooperating with the interim government."