Polish police were criticised by opposition politicians on Saturday for detaining anti-fascist protestors at a nationalist rally, while not reacting to the illegal use of Nazi symbols by other demonstrators.
In a tweet, Michal Szczerba, an opposition MP, said five people with a banner reading "nationalism is not patriotism" were "surrounded and detained" by police on Friday "without a legal basis".
Police said they had "grounds" for detaining the protestors.
The arrests occurred during a yearly far-right-led Independence March in Warsaw, Poland's capital. Organised by nationalist groups, the event has been marked by violence in the past.
Many groups who oppose the march have accused police of displaying favourable treatment toward the nationalists while unfairly clamping down on those protesting against the event.
The activists were removed from their location and held by police for several hours into the night, according to Szczerba. A professor, academic teacher, doctor, law student and a pensioner were among those arrested.
He accused Poland's ruling PiS party of creating "an oppressive state that uses force" and "harrases" peaceful protestors with arrests.
A Polish senator who also is a member of the political opposition, Krzysztof Brejza, tweeted a photo from the march where participants can be seen displaying the “Black Sun” symbol. He also noted that police did not intervene.
The sun wheel was originally used in Nazi Germany by SS, later becoming a symbol for neo-Nazis.
Promoting totalitarian ideologies is illegal in Poland.
“During the Warsaw Uprising in 1944, thousands of Poles died at the hands of German Nazis from the SS," said Brejza. "I don’t know why the police didn’t respond to such criminal symbolism in Warsaw, which suffered so much in World War II."
On the other hand, demonstrators with democratic views were forcibly removed,” he added.
Police spokesman Sylwester Marczak said the detained activists, some of whome were from the group Obywatele RP (Citizens of Poland), were held for several hours because they had restricted the work of the police. They also refused to show their identification documents.
“These are grounds for detention,” he told TVN24, an independent news outlet in Poland.
Hanna Machinska, the country’s deputy human rights commissioner, went to the scene Friday evening to intervene.
She said the protesters did not provide their IDs because they were not given a legal reason for doing so.