WARSAW, Poland (AP) — Prosecutors have opened an investigation into whether the Polish flag was publicly insulted after a family in Warsaw hung a flag from their balcony combined with a lightning bolt, a symbol for women's rights in Poland.

It's the latest incident to raise questions about freedom of expression and democracy under Poland's conservative government. Authorities have been increasingly trying to rein in anti-government protesters, including with the use of police intimidation.

Over the weekend, the police entered the Warsaw home without a warrant and removed the family’s flag. It had a lightning bolt, the symbol for the Women’s Strike movement, superimposed on the national white-and-red flag.

Aleksandra Skrzyniarz, a spokeswoman for the district prosecutor’s office in Warsaw, told TVN24 on Monday that prosecutors had opened an investigation. It’s to determine if there was a violation of a law which makes it a crime to insult, destroy or damage flags and other national emblems.

The crime can be punished by up to a year in prison.

Michal Wawrykiewicz, a lawyer with Free Courts, an initiative fighting for rule of law, said “the behavior of the police is scandalous and unacceptable in a democratic state ruled by law.” He noted that it comes as police have recently used tear gas and other force against peaceful protesters, and amid a general deterioration of civic freedoms.

“The lightning bolt on the Polish flag certainly does not offend national symbols. It is only an expression of civic disagreement with the current government that brutally violates human rights and democratic rules,” Wawrykiewicz told The Associated Press.

He said that supporters of right-wing political forces very often use their symbols on the flag, but that the police have never intervened in those cases.

Poland, he said, is experiencing now “a very massive attack on freedom of expression, it has never been so in the last 30 years. Poland is becoming Belarus when it comes to standards of human rights protection.”

The Women's Strike has organized mass nationwide anti-government protests after a high court ruled Oct. 22 to ban abortions even when the fetus has congenital defects. The ruling would further tighten one of Europe's most restrictive abortion laws.

Three women in Poland have also been charged and face up to two years in jail for “insulting religious beliefs" after sharing posters of the Virgin Mary with a halo in the rainbow colors of the LGBT flag amid a protest against anti-LGBT language by authorities.