The mayor of Warsaw banned a march that radical Polish nationalists planned to hold to coincide with the centennial of Polish independence, saying Wednesday she made the decision to curb "aggressive nationalism."

Mayor Hanna Gronkiewicz-Waltz said she wanted to put a stop to extremist displays that have appeared during the past decade at far-right events on Poland's Nov. 11 Independence Day holiday.

At a march in Warsaw last year, some nationalists carried banners calling for a "White Europe" and white supremacist symbols like the Celtic Cross.

The event brought international criticism, and lawmakers in the European Parliament called the participants "fascists" — a label that infuriated the Polish government.

This year, Poland is celebrating the centenary of its independence, gained in 1918 at the end of World War I.

"This is not how the celebrations should look on the 100th anniversary of regaining our independence," Gronkiewicz-Waltz said at a news conference she called to announce the decision.

A similar ban was announced Tuesday by the mayor of the western Polish city of Wroclaw. It is not clear if authorities will be able to enforce the prohibitions, which are subject to appeal.

The bans followed signals that radical far-right groups planned to travel to Poland for Sunday's march in the capital. Mass walk-outs by police officers in recent days also raised concerns that clashes between participants and counter-protesters could get out of hand without officers intervene.

One of the organizers in Wroclaw, former priest Jacek Miedlar, vowed to defy the city's ban, writing on Twitter that "no leftie or Jew will forbid us from this!"

Also Wednesday, a controversial statue of late President Lech Kaczynski was installed in a central Warsaw square ahead of its weekend unveiling as part of the centennial celebrations.

Kaczynski, who was killed in a 2010 plane crash in Russia, was the identical twin of Jaroslaw Kaczynski, the head of the right-wing Law and Justice party that is currently in power.

While Poles universally mourned the deaths of the president and the 95 people who perished with him, they remain divided on whether his presidency was a good one and whether he deserves hero status now.

More than 140 memorials to him exist across the nation of 37 million people.

Authorities in Warsaw's local government — in the hands of the political opposition — opposed the statue and its central location. Pro-government provincial authorities were in favor. It's a clash playing out in the courts even as the 7-meter (23-foot) statue went up.