EYES filled with tears and voices choked up with emotion as a group of Soviet parents met early this week with leaders of the Afghan mujahideen resistance, seeking information on the whereabouts of their sons.Several dozen Soviet soldiers who served in Afghanistan between 1979 and 1989 are still being held prisoner by rebel groups more than two years after the Soviet military withdrawal. Many of the anguished parents have had no contact with their sons since their capture. "We ask that you return our children," said one woman before breaking down in sobs during the meeting Monday. Despite the impassioned pleas, Prof. Burhanuddin Rabbani, the leader of a mujahideen rebel delegation in Moscow for peace talks, offered precious little information, other than to say all prisoners are being treated "humanely." Such is the nature of the first-ever visit of the Afghan mujahideen to Moscow. Though Soviet and rebel leaders have opened a face-to-face dialogue, they have made little progress toward ending the 13-year-old civil war in Afghanistan. The return of the POWs is just one issue over which the Soviets and mujahideen leaders remain deadlocked. By far the biggest barrier to a peace settlement is the future status of Afghan President Najibullah, the former secret police chief. The rebels refuse to have any dealings with Najib, who served as Moscow's point man for much of the civil war, and insist he not be part of any future political arrangement. Having defied many predictions by remaining in power after the departure of his Soviet sponsors, Najib has said in the past he is willing to step down if it would bring peace to his country. But he has yet to fulfill this pledge. Soviet Foreign Minister Boris Pankin has indicated Moscow is flexible about Najib's participation in post-civil war Afghan politics. But as a Tass news agency commentary said, it is unrealistic of the mujahideen to expect the Soviet Union, beset by domestic political and economic turmoil, to have the ability to oust the Afghan leader. Tass also dismissed other rebel demands in similar fashion, including $100 billion in war reparations and the abrogation of all Soviet treaties made with the Kabul government over the last 13 years. "The Soviet Union is not empowered to solve issues of the internal setup in another country," Tass said. "One ought to take into account that Najib and the forces that stand behind him represent a weighty political reality that can't be ignored," the commentary continued. Though the rebels' demands have been received coolly, the Soviets do not lack any desire to end completely their involvement in the Afghan civil war, says Andrei Shumikhin, an expert on conflict resolution at the USA-Canada Institute in Moscow. Toward that end both the Soviet Union and the United States have agreed to stop shipping arms to the combatants in Afghanistan by Jan. 1. m sure the people involved in the conflict are sick and tired of it," Mr. Shumikhin says. A joint statement issued in late September by Mr. Pankin and US Secretary of State James Baker III renewed calls for the formation of a caretaker coalition government to carry out free elections. A cease-fire must be in place before a settlement can be reached, Pankin told the Afghan rebel delegation, according to the Interfax news agency. Even if the Soviets reached agreement with the resistance leaders in Moscow, it is unclear how effective such a peace settlement would be. The Afghan resistance alliance is sharply divided and infighting has intensified in recent weeks. Three of the seven rebel groups based in Peshawar, Pakistan, including the powerful Hezb-i-Islam Party of Gulbuddin Hekmatyar, refused to send representatives to Moscow. In an interview with the daily Komsomolskaya Pravda, Mr. Hekmatyar said he was not against holding talks with the Soviets, but added his representatives weren't dispatched to Moscow because he didn't expect "concrete results." He also accused the Soviet Union and the US of trying to force a coalition government on Afghanistan. "In our country a coalition government is impossible because sooner or later it will show its ineffectiveness and inability to stabilize the situation," Hekmatyar said, vowing to continue fighting until the rebels achieved an outright military victory. ll never accept one government imposed on us by foreigners." But whether the rebels like it or not, the Soviet Union and the US will be needed to bring peace to Afghanistan even if only temporarily, said Shumikhin. "Even without direct Soviet and American involvement [in arms shipments], the two sides are capable of fighting forever," Shumikhin said. "They need an intermission, but they don't know how to do it themselves." Despite the difficulties surrounding a peace settlement, some positive developments have come out of the Moscow visit, some rebel leaders said. During a meeting with the Afghan delegation Russian Vice President Alexander Rutskoi apologized for the Soviet invasion in 1979. An official apology for the war is another rebel condition for a settlement. "He admitted that it was a big mistake and repeatedly said we [the Soviet Union] should not be held responsible for past mistakes," rebel spokesman Massoud Khalili said of Mr. Rutskoi, himself an Afghan war hero and former POW in Afghanistan. "It was constructive. It was effective, and it impressed Rabbani a lot," Mr. Khalili added.