In the past two months, Rhodesia has escalated sharply its war against nationalist guerrillas based in Mozambique and appears to have launched a drive to cripple the Mozambican economy and stir up opposition to the Marxist government of President Samora Machel.

Two weeks ago, Mozambican authorities issued a communique accusing the Rhodesians of waging "total war" against their country and seeking to spread "panic" among it people.

It also gave a long list of targets that have been hit since early December in four of Mozambique's 10 provinces. They include a key railway bridge on the Beira-Moztize line in central Mozambique, Mozambican Army convoys and camps, trains, road bridges, gasoline depots and civilian buses.

"They are attacking directly Mozambican economic, military and civilian installations," Mozmbique's Foreign Minister, Joaquim Chissano said in an interview here this week. "They are trying to destroy our republic."

Some of the attacks are being carried out by units of the Rhodesian Special Foreces but others are the work of agents belonging to a Rhodesian-backed opposition group in Mozambique known as "Free Africa." This group operates mainly along the border between the two countries.

These attacks have cut off coal exports from th country's biggest mine in Moatize and endangered the lives of foreign technical experts working in central and northwestern Mozambique.

A Belgian couple with the United Nations Food and Agricultural Organization (FAO) was killed last June. Since then five or six Portuguese technicians also have been fatally shot.

Some Swedish aid personnel are being withdrawn from the town of Tete after several nearby air attacks and the U.N. agricultural experts have been taken out of cnetral Mozambique. Foreign aid workers who have agreed to remain here are now escorted by armed guards.

Mozambique is clearly worried by the turn of events in Rhodesia, but shows no sign of lessening its support for the black nationalist guerrilla cause in Rhodesia. Nonetheless, the conference of nonaligned nations being held here this week comes as a welcome show of Third World solidarity with Mozambique, even if it produces little financial or material support for Mozambique, the hardest-hit of the five "frontline" states that back the querrillas.

The Soviet Union, which is not a member of the nonaligned movement, provides most of Mozambique's military hardwared, and recently has stepped up its supplies to help bolster this country's meager defense capability.

Mozambique still increased its defense spending by more than 90 percent last year. It now allocates 30 percent of its total budget, about $110 million, to military and security forces.

For a coduntry earning less than $200 million a year from its mostly agricultural exports, this is a huge sum to commit to defense and more than the health and education budgets combined.

The extent of the damage caused by the Rhodesian attacks is difficult to measure. Government communiques and independent accounts of the situation in central and northwestern Mozambique suggest that Rhodesians are out to wreck the extremely fragile Mozambican economy and bring down the Machel government.

Rholdesia has set a different objective in its raids into Zambia. While they repeatedly have bombed and occupied with helicopter-borne troops nationalist guerrilla camps there since last October, the Rhodesians have not sought to cripple the Zambian economy or hit civilian targets.

Rhodesia also has not tried to arouse opposition against President Kenneth Kaunda,, although it has sought to provoke a rift between his government and the Zambia-based guerrilla group led by Joshua Nkoma.

Rhodesian attacks into Zambia have recently decreased while escalating here. Ther is speculation this may be because Prime Minister Ian Smith hopes to hold talks in Zambia with Nkomo befor ethe elections for black majority rule the Rhodesian multiracial government has scheduled for April 20.,

Smith met secretly with Nkomo in Lusaka last August and both said afterward that they would be willing to meet again. Nakomo, however, has insisted Smith must hand over power directly to the Patriotic Front, the guerrilla alliance he leads with Robert Mugabe, and give up his plan to stage elections for a government that would exclude the front.

Rhodesian attacks aains Mozambique include the following, as related by the Defense Ministry in a Jan. 6 comunique and other accounts given here of recent incidents:

A group of eight Rhodesian soldiers, including six whites, blew up a railway bridge near M'Cito close to th Malawi border in nothehwest Mozambique, sending a locomotive plunging into the M'Combezi River together with four wagons, killing three crew members.

This has Effectively severed all rail traffic between Moatize and the coastal port of Beira, hindering most of the country's coal exports.

Free Africa dissidents attacked a bus on the main road between Beira and Chimoio in central Mozambique, killing 14 passengers.

Rhodesian planes dropped bombs on a Mozambican Army training camp at Dondo outside Beira, killing an unknown number of recruits.

A rocket attack on a convoy of 14 civilian trucks traveling between Chimoio and Tete in early January, killing or injuring scores of passengers.

Bomb explosions in the capital, Beira and Chimoio since last spring that have killed several persons and seriously injured scores of others.