Interventions are being undertaken against the most aggressive people. Most wore masks for the coronavirus pandemic.
A protest in solidarity with the activists and with LGBT people is being organised in Warsaw on Saturday.
This week, Polish police charged three people for desecrating statues and hurting religious feelings after campaigners draped several Warsaw monuments, including one of Jesus Christ, with LGBT flags. Similar protests took place in Krakow, Lublin, Wroclaw and other places.
Margo was detained at the offices of Campaign Against Homophobia but dozens of protesters then managed to block the police vehicle, prompting a short stand-off before officers cleared the way to allow the auto to pass.
Warsaw police said on Twitter that 48 people were arrested in connection with "insults directed at police as well as damage to a police car".
LGBT rights activists said they are defending themselves against intensifying anti-homosexual actions and repression coming from the government and ultra-conservative groups. President Andrzej Duda, who was sworn in for a second term Thursday, won re-election on a strong anti-LGBT platform, and social tensions have been rising.
Protesters are further angered because Szutowicz has been put into male detention.
A court order the campaigner to be held for two months in preventative detention.
Police allege she also used violence against the driver of the van, shaking and pushing him.
Activists from anti-homophobia group "Stop Bzdurom" who claimed responsibility for the flag campaign said it was part of a fight in honour of LGBT rights, an issue thrust into the heart of public debate in Poland during last month's presidential election.
Some others sympathetic to the LGBT movement also say the stunt with the statues was offensive and counter-productive.
"We are exhausted of this government", said Julia, 17, who declined to giver her full name for fear of reprisals. He accused opposition politicians who are defending the LGBT protesters of supporting "banditry". "There can be no license for this type of attack ... we have to agree with this and stand together against criminals".
Council of Europe Human Rights Commissioner Dunja Mijatovic called for the immediate release of a gay rights activist in Poland on Saturday, saying the detention sent a "chilling" signal.