MOSCOW, OCT. 26 -- The southwestern Soviet republic of Moldavia attempted today to quash an independence drive by about 150,000 ethnic Turks by declaring a state of emergency in their region and suspending their governing bodies.

The political turmoil in Moldavia, a small republic on the border with Romania, provides a vivid example of the centrifugal tendencies that have gripped the Soviet Union over the past year. The republic's Turkish minority, known as the Gagauz, set up their own "sovereign" republic in August after complaining of discrimination by Moldavia's ethnic Romanian majority.

The proclamation of the Gagauz republic, with its capital in the provincial town of Komrat, was typical of similar moves across the Soviet Union by minority groups dissatisfied with central control. Moldavia's Russian and Ukrainian minorities later followed suit by setting up the so-called Trans-Dnestrian republic.

On Thursday, the vast Central Asian republic of Kazakhstan became the 14th legally recognized Soviet republic to declare its sovereignty. The republic's legislature in Alma-Ata also banned nuclear tests in the republic, which includes the Semipalatinsk nuclear test range, long a key part of the Soviet nuclear weapons program. Environmentalists say fallout from the tests has caused higher than normal cancer rates there.

The only Soviet republic that has not yet adopted a sovereignty declaration is Kirghizia, but it is likely to do so within a few weeks. The deluge of sovereignty declarations seems likely to lead to a constitutional crisis over whether the republics' legislatures have the right to override federal legislation.

The disintegration of political power has now reached the stage where many republics' legislatures, having defied the Kremlin, are embroiled in their own sovereignty disputes with lower-level organs. Earlier this week, Gagauz leaders called for the imposition of direct presidential rule by Moscow in an attempt to circumvent the Moldavian legislature in Kishinev.

The huge Russian republic is attempting to deal with separatist threats on several fronts -- including ethnic Finns in the northern Komi autonomous republic, Tatars along the Volga River and the Buryats in Siberia. On Wednesday, the 1.4 million Chuvash, who are of mixed Finnish and Turkish extraction, declared themselves a full-fledged republic independent of Russia. Scarcely anyone else noticed.

Reporting from Kishinev this evening, the official Soviet news agency Tass said that travel into and out of the Gagauz territory would be restricted by order of the Moldavian Interior Ministry. Several thousand Interior Ministry troops have been sent to Komrat to maintain order and public meetings have been banned for two months.

Thousands of ethnic Romanian "volunteers" were reported traveling toward the Gagauz region in an attempt to disrupt elections for a new Gagauz assembly. Polling began in some areas on Thursday, despite an appeal by Moldavian President Mircea Snegur to call off the elections and begin negotiations.

Telephone communications between Moscow and Komrat were disrupted this evening after the state of emergency was declared. Earlier, a member of the rebel republic's ruling council, Pyotr Buradzhi, said he feared there could be bloodshed unless police intervened to keep the Romanian volunteers from reaching the area.

Most of what is now Moldavian territory was annexed by the Soviet Union from Romania in 1940 during World War II. The Moldavian Popular Front has called for the territory to be returned to Romania, a demand that has been fiercely resisted by the Russian and Turkish minorities.

During the past year, more than 500 people have been killed in ethnic clashes in Central Asia and the Transcaucasus. The long-running dispute over the Armenian-inhabited enclave of Nagorno-Karabakh in Azerbaijan continues to simmer. On Thursday, Tass reported that four Interior Ministry officials had been taken hostage by Armenian vigilantes.