RIO COCO, NICARAGUA -- Nicaraguan rebel leaders, facing what they describe as a potentially damaging Sandinista propaganda barrage, are working to boost the morale of their confused troops and allay the worries of commanders over a Central American peace accord.

At the same time, the top military leaders of the rebels, who are known as contras, are preparing a contingency plan to continue their guerrilla warfare against the Managua government should U.S. aid be cut off as a consequence of the accord and a peace acceptable to the contras is not reached.

Also being planned is another action designed to show the contras' compliance with the peace agreement in the interim: the freeing of about 30 Sandinista prisoners not included in an earlier release.

Three contra leaders, Adolfo Calero, Enrique Bermudez and Azucena Ferrey, discussed these and other moves in interviews on a riverbank on the Nicaraguan side of the Coco River Friday during a tour to confer with rebel commanders and guerrillas on the Honduran-Nicaraguan border.

The three met on the muddy river when a dugout canoe carrying Ferrey and several journalists came across a small plastic fishing boat traveling in the opposite direction with Calero, Bermudez and a few guards and companions.

The two boats then pulled ashore and the impromptu interviews were conducted on Nicaraguan soil near the Bocay River that was the scene of heavy fighting a few months ago.

The visits by the three leaders to this area of steamy jungle and squalid bamboo-and-thatch contra camps appeared to reflect mounting concerns that the Sandinistas are making political headway in the peace process. The rebel leaders say the Sandinistas are engaged in an intensive effort to show compliance with the peace plan through largely symbolic measures and thus ensure a cutoff of contra aid.

Calero, dressed as if for a Sunday outing in a red polo shirt and beige pants, said the Sandinistas are "carrying on a tremendous propaganda campaign aimed at trying to get our people to surrender." He said the Sandinistas were waging this campaign in part through "territorial commissions" being set up under a National Reconciliation Commission, which was formed in accord with a Central American peace plan signed Aug. 7 in Guatemala City by the presidents of Nicaragua, Honduras, El Salvador, Costa Rica and Guatemala.

Calero said the Sandinistas have been making overtures to have these commissions visit contra positions inside Nicaragua and that rebel field commanders have been sending messages asking for instructions.

"What the Sandinistas are saying is for export," said Enrique Bermudez, the rebels' top military commander. "In fact, they are increasing pressure on our troops."

In some of the latest fighting, according to a contra military spokesman, rebels armed with U.S.-supplied Redeye shoulder-fired missiles shot down two Sandinista MI25 helicopters Friday in Matagalpa province. The spokesman, Bosco Matamoros, said Saturday that Sandinista troops backed by four helicopters had tried to attack a contra force that had just received an air drop of supplies the day before. Nicaragua confirmed the loss of one copter.

According to Bermudez, "The main objective of the Sandinistas is to cut off the aid that the U.S. Congress gives to us." Then, he said, "once we disappear, the Sandinistas won't comply with the agreement."

Faced with these prospects, Bermudez said, "we are preparing a contingency plan" for a U.S. aid cutoff. "We will do the best we can to keep on fighting." He said this could mean reducing the size of contra forces, which he put at 16,000 fighters, changing tactics or waging "another type of war." He did not elaborate on the contingency planning.

He added, however that an aid cutoff "may mean it will take more time" to defeat the Sandinistas and that "this will bring some problems to us."

Bermudez, wearing a camouflage uniform and a crucifix made from a bullet, said that if the Sandinistas go ahead with plans to declare their own partial cease-fire, "we will take the opportunity to improve our offensive positions. It will not change our struggle."

The contra commander acknowledged that Sandinista actions on the political front lately have caused some uncertainty among the rebels. "The Sandinistas say we are already at peace," he said. "This is confusing our troops. We are aware the Sandinista propaganda could create some concerns. We can't deny that a few who don't have enough conviction in the struggle have been tricked by propaganda. But we are optimistic our troops will keep fighting."

Bermudez acknowledged that "we don't have the resources to make propaganda" to compete with the Sandinistas. "The best propaganda we have is military action."

In an effort to counter the Managua government's intensified appeals to rebel fighters to accept amnesty, Bermudez said, "We are conducting our own campaign to keep our fighters informed."

It was as part of this effort that he and Calero toured contra positions together Friday, while Ferrey conducted question-and-answer sessions with rebel fighters and local commanders. Calero and Ferrey are among the six directors of the Nicaraguan Resistance, the overall contra political alliance.

While the rebels have fewer cards to play than the Sandinistas in demonstrating compliance with the peace agreement, contra officials said, plans are being made to try to repeat the success of a prisoner release Aug. 18. In what they called a "humanitarian act," the rebels freed 80 alleged Sandinista prisoners held at sites on the Honduran side of the border and flew them to Costa Rica, where only 20 of them decided to return to Nicaragua.

"We have approximately 30 prisoners we are going to free at the next opportunity," Bermudez said, without giving a date.

Aside from this step, the contra leaders indicated that they are taking a harder line toward the peace plan in conversations with rebel fighters than they have thus far in public statements.

"We must change the government in Nicaragua," Ferrey told a squad of rebels in one pep talk at a contra border camp. "We can never have peace in Nicaragua with a totalitarian government like the Sandinista Front. Nothing has changed for us. The struggle continues, and the goals are the same." At one camp, however, she came in for some tough questioning by contra commanders as she addressed about 20 seemingly bewildered rebels ranging in age from 12 to nearly 50.

"We are worried because we know what communism is," declared one commander, who said he had worked in the Sandinista literacy campaign for two years before joining the contras in 1982. If the peace process and amnesty go ahead, he said, the Sandinistas "will still have the guns. It will be the same front, the same communism, and we will have our hands tied."

Another commander, codenamed Mercenario, asked, "Who is going to guarantee us that the Sandinistas are going to keep their promises?" He rejected the idea that the other four Central American presidents who signed the peace plan or groups such as the Organization of American States would apply tough sanctions for noncompliance.

"We don't trust any of them," he said.

In her response, Ferrey said the rebel directorate would never agree to an amnesty without "complete security." She said this meant that, among other measures, the Sandinistas had to dismantle their neighborhood committees and state security apparatus, cut all links between the ruling party and the Army, free all political prisoners and return all confiscated property.