In a bid to protect its natives' tongue, the tiny republic of Estonia has decreed that all Russians and other non-natives who work in stores, government or other service jobs learn Estonian in four years or be sacked.

The restive Baltic republic's legislature voted on Wednesday by 204-50, with six abstentions, to adopt the unprecedented law, said Felix Undusk, a commentator for state-run Estonian television.It was another pioneering move by Estonia's legislature, which in November challenged the central government in Moscow by declaring sovereignty over all but foreign affairs.

There was no immediate reaction from the Kremlin to Estonia's latest action. Official Soviet media reported on the new law, but did not mention the sanctions against workers who do not learn Estonian.

Radio Moscow said the republic's Supreme Soviet adopted a law making Estonian the official language but that the law "points out that such a status does not infringe on the rights of people whose mother tongue is not Estonian."

Estonia's standard of living, enviably high by Soviet standards, has led to an influx of immigrants, and many Estonians fear they will one day be outnumbered in their own homeland.

About 65 percent of Estonia's population of 1.5 million is ethnic Estonian. Russians make up 28 percent, Ukrainians 3 percent and Byelorussians 2 percent.