Police forcibly removed activists who tried to block a march by far-right extremists marching Tuesday on Poland's Armed Forces Day holiday.
The activists, many of them women, held up photos of Heather Heyer, the American woman killed when a car plowed into a crowd of people protesting a white nationalist rally in Virginia on the weekend.
Beneath the photos were the words: "If you're not outraged you're not paying attention. Heather Hayer, victim of fascism August 2017."
"Get fascists off our streets," read another sign.
The aim of the protest was to prevent a group of several dozen extremists from marching in central Warsaw.
In recent years Polish far-right groups have become increasingly active, particular on the national holidays. Critics of the ruling conservative Law and Justice party believe the government is emboldening them by failing to denounce them in strong terms.
Police forcibly removed the protesters, taking them to a side street and recording their names, but as they did so new protesters arrived to take their places. Police heavily guarded the extremists.
Earlier in the day, President Andrzej Duda bestowed a high honor, the Commander's Cross with a Star of the Order of Merit, on Lt. Gen. Ben Hodges, commander of the U.S. Army in Europe. A spokesman for the president said the award recognizes Hodges' commitment to Polish-U.S. military cooperation and his role in strengthening the NATO and U.S. presence in Poland.
Some 1,500 Polish soldiers then paraded in Warsaw, while fighter planes and other aircraft flew in formation above.
Poland's marching soldiers were joined by a small unit of U.S. troops, some of the thousands who deployed to Poland this year as part of efforts to reassure European countries concerned about possible Russian aggression.
U.S. Ambassador to Poland Paul Jones said on Twitter that the Americans were proud to march alongside their Polish allies.
The August 15 holiday celebrates Poland's landmark victory against the Russian Bolsheviks in the 1920 during the Polish-Soviet war. In the Battle of Warsaw, often called the "Miracle on the Vistula," outnumbered Polish troops led by Pilsudski defeated an advancing Red Army.