SOVIET COUPAt least 50,000 Russians defied the Soviet Union's new communist hard-line rulers Aug. 20 and demonstrated at the Russian parliament against the overthrow of Mikhail Gorbachev. Tens of thousands of people also rallied in Leningrad, journalists said. Soviet miners Aug. 20 followed a general strike call by Russian President Boris Yeltsin, but in the key Tyumen oil fields a labor official said workers backed Yeltsin but stopped short of a strike, fearing they could pitch the country into civil war (see stor y, Page 1).... Soviet banks on Aug. 21 will temporarily stop sales of hard currency to Soviet citizens traveling abroad on personal business, the official Tass news agency said Aug. 20.... The European Community will demand to see deposed Soviet President Gorbachev and could hold a summit this week to discuss the Soviet Union, French Foreign Minister Roland Dumas said Aug. 20.... NATO foreign ministers will hold emergency talks Aug. 22 to discuss Gorbachev's removal. Ambassadors from the 16 nations of the W estern alliance, saying they were determined to preserve the achievements of the Gorbachev era, also served notice on Moscow that it must respect all international obligations and human rights.... German Chancellor Helmut Kohl Aug. 20 became the latest Western leader to call on the hard-line Communists who overthrew President Gorbachev to restore him to power. New Soviet leader Gennady Yanayev has informed Chancellor Kohl that Gorbachev is in safety and not under any threat, a German government spokesman sa id. A Berlin radio station is broadcasting Russian-language news for Soviet troops in east Germany to counter the seizure of Soviet media by hard-liners.... European nations fear a huge outflow of Russian refugees following the assumption of power by hard-line communists in the Soviet Union, Sadako Ogata, the UN's High Commissioner for Refugees, said in Tokyo Aug. 20.... Officials from Poland, Hungary, and Czechoslovakia will meet in Warsaw Aug. 20 to discuss the impact of the Gorbachev ouster, the Czechosl ovak state news agency CTK said. The three former communist countries will discuss coordinating measures to meet a possible influx of Soviet refugees as well as how to secure continuing supplies of Soviet raw materials. US President Bush has assured Czechoslovakia that the US regards democratic moves in Eastern Europe as irreversible, the state news agency also said.... News that Gorbachev had been ousted came to Cambodia several hours before the Moscow-backed government in Phnom Penh announced Aug. 19 a bi g concession to its opponents to facilitate a peace settlement. But the leaders did not know of the ouster, which could complicate a settlement.... A senior Soviet official arrived in China Aug. 20, on the heels of the removal of President Gorbachev, for a visit that was billed as routine. Deputy Foreign Minister Alexander Belogonov would discuss Mideast problems with his counterpart Yang Fuchen, a Soviet Embassy official said.... Egypt said Aug. 20 that the quest for peace between Israel and the Arabs shou ld go on despite Gorbachev's downfall.