Thousands Strike Over Soviet Price Boosts : Protests: Workers in a major industrial center gather in a main square to demand higher pay.

MOSCOW —  Tens of thousands of Soviet workers went on strike Thursday in the industrial center of Minsk to protest the government’s massive price increases earlier this week as labor unrest threatened to spread.

As the strikes closed most of the major factories in Minsk, a key manufacturing center in Soviet Byelorussia, an estimated 30,000 workers gathered in the main square to demand higher pay, according to the independent news agency Interfax.

The protest, all the more dramatic in such a conservative and quiet city as Minsk, could signal the spread of industrial unrest from the country’s coal mines, more than a quarter of which have been on strike for a month, to other sectors of the economy following increases of as much as 200% or 300% in state-set prices for food and consumer goods.

Brief protest strikes have been rippling across the country all week, according to Radio Moscow and the official Soviet news agency Tass, and the government has been expecting major demonstrations.

“Workers feel betrayed,” a spokesman for the new Byelorussian Confederation of Labor said by telephone from Minsk. “When President (Mikhail S.) Gorbachev was here in February, he asked for our help, and people were ready to give it. A few weeks later, his government increases the price of food and other daily necessities to the point where it is barely possible to live.

“Where is the social contract? What do we get for our work? If the government has made mistakes, we are sorry, but why must we bear the burden? And where, workers want to know, are these reforms taking us that life only gets harder?”

The strikes had begun on Wednesday at Minsk’s huge tractor factory and spread through the day. On Thursday, the workers were joined in their march to the center of the city, the capital of Byelorussia, by students, doctors and even government clerks.

A towering statue of V. I. Lenin, the Bolshevik leader who founded the Soviet state, became the platform for speakers at the rally, and the demands quickly turned from economic to political, with calls for Gorbachev’s resignation and that of the Soviet and Byelorussian governments.

Byelorussian Prime Minister Vyacheslav Kebich was shouted down as he sought to explain the need for the harsh measures and his government’s efforts to ease the burden; the government later offered to open talks with the strikers.

The country’s striking coal miners said, meanwhile, that the doubling of pay over a year and other benefits proposed by the government on Wednesday were not enough and they would not return to work. They said there are no plans for further talks.

Pavel Shushpanov, head of the Independent Miners’ Union, dismissed the government’s offer as falling far short of the strikers’ economic demands and ignoring their calls for Gorbachev’s resignation and the dissolution of Parliament.

Alexander Mrill, a strike leader from the Donetsk field in the Ukraine, said recent steep price rises by the government on a wide range of goods made a mockery of an offer to double miners’ pay within a year in return for a pledge to boost production.

State television showed Gorbachev telling striking miners at a Kremlin meeting on Wednesday that no amount of hissing and jeering by demonstrators would force him to resign.

“Everything must be decided by the constitution,” Gorbachev said of the miners’ political demands, which include his resignation. “Everything else is demagogy. Somebody may try to knock me off the rails, but this is nothing new to me. . . . No jeering or shouting on squares will knock me off the rails.”