The following article is based on information arriving from Poland.

Riot police in central Warsaw used nightsticks and tear gas to disperse thousands of people who defied the martial-law curfew Thursday night to mark the 11th anniversary of the 1970 food riots on the Baltic Coast in which dozens of persons died.

Witnesses said riot police hurled tear gas into a side entrance of Holy Cross Church in Warsaw's old town, where people had gone for refuge. Police officers reached in through the front doors to pull out some of those inside and arrest them, but they did not enter the church.

There were reports of street fighting and shooting incidents in cities outside the capital Thursday. Travelers from Gdansk reported that pamphlets had been distributed throughout the city calling on people to gather beneath the giant monument to fallen shipyard workers which was dedicated in a great show of national unity exactly one year ago.

Western diplomatic and Solidarity sources said gunfire was heard from the Wujek coal mine near Katowice in the southern industrial region of Silesia. As at other mines in the region, workers were said to have occupied the mine shaft. Persons familiar with official thinking in Warsaw said that authorities fear that the miners might flood the mines if they were attacked. They described Silesia as potentially the most dangerous area of confrontation in the country.

Reports from a variety off sources said as many as 16 mines were on strike and that the workers were occupying the shafts in half a dozen. The mines were said to be surrounded by police and families are prevented from bringing food to them.

Riot police and Army troops in Warsaw sealed off the area around Victory Square -- site of the Tomb of the Unknown Soldier -- and the old town, preventing others from going to a special mass at Holy Cross.

Solidarity's Previous call for mass demonstrations on the anniversary, including a 4 p.m. rally at Victory Square, was one of the factors which led to the imposition of martial law last Sunday.

Witnesses said people gathered in Victory Square and in groups of a dozen or so began lighting candles at a memorial cross there commemorating the late cardinal Stefan Wyszynski. At about 4 p.m. a column of police emerged from trucks parked around the square and marched in wearing helmets and carrying shields and nightsticks. They dispersed the crowd on the square without violence, but witnesses said they used the clubs to disperse the crowd that had gathered near the church. They said tear gas also was used.

Police jeeps and armored personnel carriers ringed Victory Square, blocking the streets to pedestrians. The gun turrets were swung around to threaten the gathering crowds.

At one point, as a crowd gathered outside the Holy Cross Church, which is near Warsaw University, trouble began as a group of students began chanting, "Poland, Poland," "Freedom for Lech Walesa," and "Long Live Solidarity." A militia jeep mounted with a loudspeaker sped up to the church and warned the crowd that they were breaking martial-law regulations by gathering in a public place.

The warning, broadcast over a loudspeaker, was met with jeers and whistles. The crowd, which was several thousand strong, broke out in the Polish national anthem, which momentarily drowned out the loudspeaker.

The militia chief then ordered up squads of riot police. "In the name of law and order and the Polish People's Republic, I order you to leave this place," he said. " I warn you once, I warn you twice..."

At this point, the riot police began chasing the students and bystanders gathered in the street, firing tear-gas cannisters in their wake. The crowd ran off as fast as possible, chanting "Long Live Freedom" and "Gestapo. Gestapo."

During the first charge, the police left the students gathered on the church steps around a Polish flag draped to the statue of a saint. But on the second charge, they cleared the steps and, according to weeping women, beat up several students.

In a separate incident near the church, a bearded man stepped in when a police officer started beating one demonstrator, dragging the victim out of the policeman's grasp so he could escape into the crowd. When the policeman raised his arm so as to strike the bearded Pole, the man offered him a flower. The stunned officer simply turned away.

In other parts of town, churches were full. The priest at Three Crosses Church, about a mile away from the scene of the demonstration, told the congregation that they must pray that a tragedy like December 1970 "must never happen again."

Members of a team of Dutch Red Cross officials who drove a convoy of about 60 trucks laden with charity food parcels to distribution locations in 32 cities around the country said the situation in places they visited looked much the same as in Warsaw.

"Every place is completely ringed with troops and Army hardware," said one member of the team, whose original itinerary was cut in half by the military authorities. "And the farther you get into the country, the more roadblocks there are."

The authorities began their show of force against the Thursday demonstrations as early as Wednesday night by sending a huge convoy of armored cars, water cannon, command cars and trucks filled with troops through the city. The convoy, with blue flashing lights atop the vehicles, passed for 20 minutes.

As the authorities were attempting to ward off the demonstration, however, Solidarity was passing the word to sympathizers to light candles in their windows and turn off house lights at an appointed hour Thursday night as a sign of protest.