Nicaraguan rebel leaders, concerned about reported abuses by their forces, say they have set up their own Red Cross and a human-rights commission to curb practices such as execution of prisoners.

Civilian leaders of the contras, as the rebels are widely known, are pressing the International Red Cross to start serving as an intermediary for handing over captured soldiers to Nicaragua's Sandinista government. But the contras' military commander said that his troops in the field lack facilities for keeping prisoners and that captured troops should simply be let go after being stripped of their weapons and equipment.

The Nicaraguan Democratic Force, known by its Spanish initials FDN and the largest group battling the leftist Sandinistas, set up the two new organizations this summer in part because it was worried about international criticism over persistent reports of human-rights abuses by contra guerrillas inside Nicaragua, the rebel leaders said. In particular, the contras repeatedly have been accused of executing captured soldiers, militiamen and Sandinista officials or party militants.

Dr. Indalecio Rodriguez, the director general of the contras' Red Cross, said that a principal objective of the new organizations was "to correct errors that there have been on the part of our force."

"We want to educate our people in this respect," he said, adding, "We don't accept that all of the reported cases of abuses have been the responsibility of our forces."

The FDN's Red Cross will seek to carry out the duties of a national Red Cross although it cannot obtain formal recognition because it is linked to a guerrilla rebel force instead of a recognized government, Rodriguez said. It will oversee deliveries of medicine, farm implements and other humanitarian aid to peasants whom contra units meet in the countryside. Some of this aid will be financed by $27 million approved by Congress this year as humanitarian assistance for the contras.

It remains to be seen whether the new human-rights effort will affect the contras' behavior in the field or will serve only as a public-relations vehicle. On Aug. 2, several weeks after the two organizations were formed, contra forces executed 11 captured Sandinista militiamen and party militants after briefly overrunning the town of Cuapa 80 miles east of Managua, according to residents and local officials there.

The contra leaders said that they had "no information" about the Cuapa attack, but Rodriguez said it was "possible" that prisoners there had been executed.

Rodriguez and the other rebel leaders granted interviews on the condition that the location be kept secret. The contras currently have most of their troops inside Nicaragua but also have bases in neighboring Honduras.

The stepped-up public concern for human rights on the part of the Nicaraguan Democratic Force is partly due to pressure from the Nicaraguan opposition political leader Arturo Cruz, according to reliable sources familiar with the FDN's operations.

Cruz, who led a coalition of political parties that boycotted Nicaraguan elections last year, formally allied himself with the FDN this year. In meetings this month with FDN military commander Enrique Bermudez, Cruz stressed the importance of respecting human rights, according to the sources, who asked to remain anonymous.

Headed by Carlos Icaza, the Human Rights Commission will assist the Red Cross in educating contra guerrillas about the laws of war and the importance of respecting civilians' rights. The commission and Red Cross plan to distribute thousands of copies of a manual for soldiers developed by the International Red Cross. The commission will seek to call attention to Sandinista human-rights abuses, such as carrying civilians in military convoys, Icaza said.

The Human Rights Commission technically is not part of the FDN but of the Unified Nicaraguan Opposition, or UNO, an umbrella group of civilian contra leaders formed this year to encourage rebel unity. Cruz is one of the three leaders of UNO, together with FDN chief Adolfo Calero and opposition politician Alfonso Robelo.

In addition to heading the human rights commission, Icaza has been named the contras' "prosecutor." His job is to level criminal charges against errant guerrillas, who are then tried in military courts composed of three to five contra commanders.

So far, Icaza has brought charges in five cases, including one for manslaughter in which the defendant was found guilty of accidentally killing a comrade, Icaza said. The convicted man was demoted and sentenced to a year of forced labor in contra camps, he said.

Other cases have been brought against contras for planting marijuana, deserting one contra unit to join another, sexually harassing a woman and theft, Icaza said.

The contras are seeking to use two Sandinista soldiers captured in March in northern Jinotega province as a test case for establishing a process for handing over prisoners, Rodriguez and Icaza said.

Nicaraguan Foreign Ministry spokeswoman Angela Saballos said in a telephone interview from Managua that the ministry had not yet received any communication from the Red Cross on the matter.

In any case, it was unclear whether the effort to set up the mechanism to hand over prisoners would be successful, since military commander Bermudez expressed doubt about his units' ability to take care of prisoners while deep inside Nicaragua and seeking to evade Sandinista forces.

"Our forces inside don't have the capacity to keep prisoners," he said in an interview.