MOSCOW, FEB. 26 -- Hundreds of thousands of Armenians ignored an unprecedented appeal by Soviet leader Mikhail Gorbachev today and persisted in their week-long street demonstrations demanding the restoration of land now part of a neighboring republic.

Gorbachev's personal call, the first time he has intervened in a nationalities dispute since taking power nearly three years ago, appeared to reflect growing concern in the Kremlin over the surging protests. Four Soviet officials with Politburo rank have flown to Armenia to deal with the crisis, and witnesses quoted in news reports said Soviet paratroopers have been dispatched to the Armenian capital of Yerevan.

Gorbachev, already confronted by nationalist protests in the Baltic republics and parts of Central Asia, broadcast a plea for "reason and common sense" to television viewers in the republics of Armenia and Azerbaijan. The statement, read by senior Kremlin official Vladimir Dolgikh, said that the Soviet leadership was worried that the demonstrations "may lead to serious consequences."

"We do not wish to evade a frank, sincere discussion of various ideas and proposals," Gorbachev said. "But this must be done calmly . . . Fomenting of dissension and distrust between peoples will only interfere with the solution of these problems."

Nationalist demonstrators want Nagorno-Karabakh, a predominantly Armenian enclave inside Azerbaijan, reunited with the Armenian republic.

In a resolution passed today, the Armenian Communist Party Central Committee asked Moscow to establish a commission to look at the problems causing the unrest.

Shortly afterward, local party leader Karen Demirchyan appeared before a large, peaceful crowd in Yerevan and announced the decision. The gesture by Demirchyan, who has been under attack by Gorbachev and other party leaders in Moscow, was interpreted as a rare challenge to the Kremlin.

With its proud population of 3 million, Armenia has become a major test case for the country's leadership, which seeks to offset traditionally strict controls over nationalism with a limited degree of independence in the outlying republics.

Despite Gorbachev's televised appeal, Armenians continued to stream into Yerevan today, dissident sources said by telephone. The outpouring that began Feb. 18 with about 5,000 participants was estimated to number in the hundreds of thousands at today's gathering, official journalists acknowledged.

Both officials and protesters appeared to be avoiding violence. Army troops deployed in the Armenian capital yesterday morning apparently moved into the background or to outlying areas today, dissident sources said.

{Sergei Grigoryants, editor of the human rights magazine Glasnost, quoted airport officials in Yerevan as saying that 29 planes carrying Russian police and troop reinforcements had flown to Yerevan Friday, the British newspaper The Guardian reported.

{There were 1,500 paratroopers on standby at the Dynamo sports stadium, and all public buildings were being guarded by police patrols, according to Grigoryants, who was in Yerevan.}

"The accent is against violence," one of the sources said. "There has not been one single clash since the whole thing started."

Soviet troop contingents were being dispatched to Nagorno-Karabakh, where ethnic tensions are still strong, according to Azerbaijani sources in Baku and Moscow.

"Sons, nephews and grandsons from all over the republic are being sent to maintain order," said an Azerbaijani woman who asked not to be identified. "I should know, my son was sent, too."

{In Washington, the Armenian National Committee of America said Friday it had learned from witnesses that 70 Armenians have been killed by mobs in ethnic conflicts in Nogorno-Karabakh and that villagers have fled to the city of Stepanakert for refuge.}

In his nine-minute broadcast statement, Gorbachev promised that the nationalities issue will be examined carefully by Soviet leaders in an upcoming meeting of the party Central Committee.

The question will be settled, he added, "in the spirit of old traditions and according to the principles of Leninist policy on nationalities.

"I call on you to display civic maturity and restraint, return to normal life and work and observe social order," the Soviet leader said in ending his remarks. "The hour for reason and sober decision has struck."

In the streets of Yerevan, Gorbachev's appeals for calm, broadcast several times over the course of the day, apparently had little noticeable effect.

"We believe what he said and we trust him," said Armenian activist Armen Karen in a telephone interview. "But, in fact, the solution to the problem is quite simple. They should give Nagorno-Karabakh to Armenia, and they haven't agreed to do that yet. Until they do, we won't give up."

Although Soviet authorities have closed Armenia to foreign journalists, a picture of the scene in Yerevan has emerged from lengthy telephone interviews with witnesses.

According to local residents' accounts, a crowd has concentrated daily in the Yerevan town square near the city's opera house, with thousands of demonstrators spilling through the steets and up the hillsides of the city. All-day political rallies in front of the opera house attract dozens of Armenians to the lectern, including local writers, nationalists and dissidents.

Other demonstrators use banners and posters to deliver their messages. "Nagorno-Karabakh," says a popular slogan, "belongs to Armenia."