Polish security forces shot and killed seven striking workers and wounded 39 others yesterday as pitched battles erupted near the southern city of Katowice, and hundreds of civilians and militiamen were wounded in riots in the Baltic port of Gdansk, Radio Warsaw reported today.

The radio account of the deaths in Katowice yesterday indicated that open resistance to the five-day-old military takeover of the Polish government was intensifying, as was the government's repression of the Solidarity trade union organization and its supporters. Increased military patrolling and continuing arrests spread a fresh wave of fear through Warsaw today.

Police blocked off sections of Warsaw today hours before a planned mass rally that Poland's Catholic Church and Solidarity had called to commemorate the deaths of striking workers killed by security forces in 1970.

Police in Warsaw used clubs and tear gas to break up demonstrations in Victory Square, according to reports reaching Washington. Thousands of people defied the curfew to gather in the area to mark the anniversary of the 1970 uprising. Eyewitnesses said police at one point tossed tear-gas canisters into a side entrance of Holy Cross Church in Warsaw's old town. Details, Page A44.

Church officials had said that they would read out to the crowds a toughly worded appeal to the military government to free Solidarity leader Lech Walesa and the thousands of others who have been arrested and to cease "terrorizing" the nation. That appeal was hand-delivered yesterday to foreign journalists in Warsaw.

Radio Warsaw said the violence in Katowice and Gdansk yesterday was "to be regretted most profoundly" but placed all of the blame for the bloodshed on "provocateurs" and broadcast new claims of evidence that Solidarity had been plotting a coup d'etat. Commentaries on the radio muted earlier suggestions of eventual reconciliation with Solidarity, vowing instead that "the authorities will not retreat since there is nowhere to retreat . . . . Socialism will not be overthrown."

"The forces of order dispersed groups that were behaving aggressively," the radio said, adding that 164 civilians and 160 militiamen were injured in Gdansk.

Poland's East European allies echoed these charges throughout the day, asserting that Gen. Wojciech Jaruzelski, premier and head of the Communist Party, had decreed martial law early Sunday to head off a civil war that Solidarity had hoped to provoke, news agencies reported. The Soviet news agency Tass accused Western nations of hoping for "a bloodbath" in Poland.

The status of Walesa, believed to be held under house arrest, remained unclear. Reports circulated here that the government was attempting to force him to go on television to call for an end to resistance to martial law, but there was no confirmation of this. Walesa has not been seen in public since the Solidarity leadership conference in Gdansk on Saturday that called for a national referendum on the role of the Communist Party in Polish political life.

The web of arbitrary arrests entangled one Polish journalist early yesterday when three secret policemen showed up at his Warsaw apartment and demanded that the journalist sign a statement saying he would stop committing actions against the state. He refused to make this incriminating statement and was immediately arrested and taken away by the police, who seemed only a few weeks ago to have lost all of their power as Solidarity pushed for civil liberties.

Radio Warsaw carried a new pledge from the military council that Jaruzelski has named to run the country for an unspecified interim period that "there is no return -- nor can there be -- to the erroneous and ineffective methods of economic management of before August 1980."

In Warsaw, streets leading into the U.S. Embassy were blocked off in midmorning. Police began noting the passport numbers of people asking to enter the embassy on Wednesday.

Troops patrolled the center of the city on an expanded basis, and identity checks were more frequent for pedestrians today. Two armored personnel carriers with troops aboard were parked in Victoria Square, the decorative center of Warsaw's commercial district. Warsaw televison reported that eight persons were arrested when they attempted to stage a demonstration in the square.

The news account of the battles at the Wujek coal mine, near Katowice in Upper Silesia, said that strikers had injured 41 police officers, a dozen seriously, when they fought back with axes, crowbars and stones as the troops sought to take over the mine the workers had occupied. "Firearms were used only when it came to a clear need for self-defense," the radio said.

"Let the blood shed in Silesia cause the provocateurs to sober up and bring home to the madmen that the road to confrontation leads nowhere," the radio said.

With all telex and telephone lines cut and Solidarity activists in hiding or already under arrest, it was impossible to obtain an independent account of the trouble near Katowice, or of the street disturbances that broke out when civilians staged demonstrations in Gdansk last night. A nighttime curfew is in effect.

A Danish labor union was quoted by The Associated Press as saying it had learned from informed sources that four workers were killed when troops stormed a Gdansk factory. A Belgian of Polish descent who arrived in Brussels Thursday after a trip to Wroclaw told AP that he saw five military helicopters land on the grounds of Wroclaw's strike-bound Pafawag railway coach factory Monday and then heard automatic weapons fire. The Belgian said 30 workers were reported to have been killed in the assault, but there was no way to authenticate this report.

Taxis have disappeared from the normally clogged streets and automobile traffic has dropped by about 80 percent as gasoline has been taken off the market for private motorists. Government cleanup squads have stripped the streets of Warsaw bare of Solidarity posters.

Eight charter flights left Warsaw to carry foreigners to Western Europe, Moscow and Istanbul today. Travelers had to pass through four roadblocks from the city's center to the airport. Passengers included a large number of students who had been vacationing in Poland.

News services reported the following developments:

Western diplomats in London said that reports in Warsaw spoke of 15,000 to 75,000 people arrested since Sunday and said that two holding camps had been set up to hold the detainees. One report put the camps near Warsaw and in the Hel Peninsula near Gdansk.

East Germany's official news agency ADN, quoting a Politburo member, put the number of detainees at 3,500.

Diplomatic sources said that two of the Polish Communist Party's 15 Politburo members, Hieronim Kubiak and Jan Labecki, both regarded as leading party liberals, may be among those under arrest.

A British Broadcasing Corp. correspondent, in a taped dispatch from Warsaw, said the Soviet commander-in-chief of Warsaw Pact forces, Marshal Viktor Kulikov, was in the Polish capital late last week and was reported to have given Jaruzelski an ultimatum to act against Solidarity or face a Soviet move into Poland. There was no confirmation of this report.

The Czechslovak Communist Party newsaper Rude Pravo reported that cobblestones and pieces of iron were thrown at police from a workers' dormitory in Katowice yesterday, injuring six officers.