MOSCOW — Military helicopters circled over Tadzhikistan's capital of Dushanbe on Monday after hard-line Communists imposed a state of emergency and forced the republic's president to resign, spreading political unrest to another far corner of the crumbling Soviet empire.
The ouster of acting President Kadreddin Aslonov, in favor of a discredited former Communist Party boss, was the first organized act of defiance anywhere in the Soviet Union by the embattled party, which is determined not to give up power in conservative Central Asia without a fight.
Thousands of demonstrators took to the streets in protest of the Communist resurgence, paralyzing traffic through Dushanbe's central square and drawing a major deployment of special security troops. The Soviet news agency Tass said military aircraft also hovered over the city.
While tensions heightened in Tadzhikistan, progress was reported toward solving the Soviet Union's most deadly ethnic conflict.
In the Russian spa town of Zheleznovodsk, the presidents of Armenia and Azerbaijani shook hands for the first time ever and signed an agreement to stop the fighting and disarm the combatants in the Nagorno-Karabakh region.
But it was a day marked by political tumult in other Soviet republics:
* Demonstrators for and against Georgia's hard-line president, Zviad Gamsakhurdia, continued a tense, armed standoff in the center of that republic's capital, Tbilisi.
* In northern Georgia, relations between Ossetians and the ethnic Georgian minority remained "extremely tense," Tass reported. Gunfire was heard in several villages of South Ossetia, and militants on both sides were accused of hostage-taking.
The unrest in Tadzhikistan, potentially the most dangerous, drew masses from both extremes of the political spectrum into open confrontation.
Although the republic's Communist Party renamed itself the Socialist Party over the weekend, Aslonov went ahead with a decree disbanding the party and seizing its assets.
Jubilant anti-Communists celebrated by toppling several monuments to Soviet founder V. I. Lenin, including one in Dushanbe's central square that reformist Mayor Maksud Ikramov had ordered removed.
But, as in other distant areas of the Soviet Union, Communists still control the legislature in Tadzhikistan and other republics of conservative Central Asia. Angered by efforts to strip them of their clout and privilege, Communist deputies called a special Parliament session and announced a state of emergency to run until Jan. 1.
They demanded Aslonov's resignation and, after getting it, replaced him with Old Guard leader Rakhman Nabiyev, who had been pushed into retirement shortly after Soviet President Mikhail S. Gorbachev rose to power in 1985 and began his wide-ranging reforms.
Nabiyev was instructed by the Communist deputies to take up presidential duties until elections, which are to be held Oct. 27. It was not clear whether any challengers to Communist Party candidates would be allowed to run.
Aslonov had served as acting Tadzhik president for only a month. He was named to the post after Kakhar Makhkamov was forced to resign for supporting the failed August coup against Gorbachev.
The Parliament also called for prosecution of Mayor Ikramov for inciting crowds to defile monuments to Lenin, and it ordered all Communist memorials reinstated and put under guard.
The choice of the 61-year-old Nabiyev, one of the first targets of Gorbachev's attempts to weed out corrupt party bureaucrats, signaled a major retreat to authoritarian leadership in the republic of 5 million.
After repealing Aslonov's orders for disbanding of the party and nationalizing its wealth, the hard-liners sent telegrams to Gorbachev, Yeltsin and other Soviets identified with democratic reform to announce that economic and political ties with them are being "reduced," the Russian Information Agency reported.
They also warned the KGB and other Soviet police agencies not to interfere with the "internal affairs" of Tadzhikistan, which declared its independence from the Soviet Union earlier this month.
At least 10,000 anti-Communist protesters responded to a call by opposition groups for a rally in front of Parliament, according to Tass. The demonstration was organized by the Rastokhez popular movement, the Democratic Party of Tadzhikistan and the illegal, fundamentalist Islamic Revival Party.
Ignoring the state of emergency's prohibition against public gatherings, they put up barricades in the city center, paralyzing traffic. In response, the government deployed special security troops, and military helicopters hovered over the crowds, Tass said.
The agency reported late Monday that tensions had calmed slightly and the patrolling aircraft had flown off, "but it was not certain that the night would pass in absolute calm."
A similar confrontation has gripped Georgia for three weeks, with pro- and anti-government demonstrators massed in the central streets of the capital, Tbilisi.
At the talks over Nagorno-Karabakh in Zheleznovodsk, Russian Federation President Boris N. Yeltsin announced early today that the presidents of Armenia and Azerbaijan had signed an agreement to work for an end to the four-year war that has cost about 1,000 lives.
The agreement mediated by Yeltsin and Kazakhstan President Nursultan A. Nazarbayev calls for a cease-fire, disarmament of combatants by the end of the year and local elections, Tass reported. The two sides also reportedly agreed to work toward settling refugees who have fled the fighting.
Although Yeltsin called the agreement "a historic act and a historic document," Armenian President Levon Ter-Petrosyan said, "Serious work lies ahead."
Nagorno-Karabakh is a mountainous enclave peopled predominantly by Christian Armenians but located entirely within Muslim Azerbaijan. The region was transferred from Armenian to Azerbaijani control after Azerbaijan joined the Soviet Union in the 1920s.