The rally held in Warsaw every year to mark Poland's Independence Day on November 11 has often been marred by violence by nationalist extremists in the past.
But this year's celebrations were "among the safest in recent years," according to the Warsaw police spokesman, Sylwester Marczak.
"Today's events were safe as far as what was happening on the streets of Warsaw. Nothing surprised us despite the events arousing much emotion," Marczak said.
At the same time he said that the police had detained several people on various charges including drug possession and that the burning of a German flag was one of a number of incidents that "are being analysed."
More than 100,000 gathered in Warsaw for the march on Thursday afternoon, according to the organisers. The marchers, carrying Poland's white-and-red national flags, passed through the city's central Jerozolimskie Avenue and proceeded across the Vistula River to end the march at the National Stadium.
The march was organised by nationalist groups, and this year took place under state patronage so it could take place after a court banned it.
Deputy Interior Minister Blazej Pobozy told PAP that the march was "the safest in history."
"The march was legal and, therefore, safe and peaceful," he said.
"State patronage made it possible to properly celebrate our most important holiday, in the traditional formula to which many Poles who come to Warsaw every year on November 11 have got used to," he added.
Meanwhile, the Anti-fascist Coalition organised its own march, held under the slogan "For Your Freedom and Ours," which took an alternative route in central Warsaw.
"We have a lot of anger and frustration about what the government it is doing together with its people who do dirty work for them - nationalist organisations," the organisers of the anti-fascist demonstration said explaining the idea behind their event.
At the same time they said they did not want to "get caught up in their spiral of hatred and aggression," referring to the previous official celebrations where violence has broken out. (PAP)