"Stop tightening abortion laws," read the red hand-shaped signs that protestors in Poland carried on Friday as they marched through the streets of Warsaw and other Polish cities to protest the ruling conservative government's initiative to tighten the country's already strict laws against abortion.

The nationwide demonstrations, drawing thousands to the streets, were dubbed "Black Friday," a reference to the black attire that has often been donned by the protesters since 2016. The protests that year forced the government to abandon a plan to make all abortions illegal.

However, Poland still has some of the most stringent abortion laws in the European Union (EU). Currently, they allow abortion only in the case of risk to the mother's life or if the pregnancy is the result of rape or incest.

Read more: Polish abortion laws provoke mass Women's Day protests

Friday's protesters spoke out in opposition to the proposed legislation changes, which would ban abortions for irreparably sick or impaired fetuses, or those with Down Syndrome.

Hundreds turned out in Wroclaw, a city in western Poland, with some carrying signs reading, "I will not give birth to a dead baby."

Others in Warsaw held a banner stating "Women's Strike," the name of the organizing movement that fights a further clamp-down on abortion rights. The protesters in the capital marched through the streets chanting and blaring bullhorn sirens.

Protesters hold a sign reading 'Women's Strike'

From the bishops' seat to parliament and PiS headquarters

The march in Warsaw began at the seat of the Roman Catholic bishops, who back stricter anti-abortion laws in the strongly Catholic country. The procession then headed to parliament before ending at the headquarters of the ruling right-wing Law and Justice (PiS) party headed up by Jaroslaw Kaczynski.

A woman waves a black banner as protesters fill the streets in Poznan

Last year, the PiS government launched a campaign urging Poles to "breed like rabbits" in order to raise the country's declining birth rate. Additionally, in a program called "Family 500+," the state pays out around 500 zloty (€118, $146) per child per month to families with two or more children.

The government has also cut funding for in-vitro fertilization.

The PiS-proposed restrictions have supporters. Stop Abortion committee activist Kaja Godek told AFP that if passed, the new rules stopping abortions of malformed fetuses would "represent the lives of three human beings every day."

However, the Council of Europe's human rights commissioner, Nils Muiznieks, expressed his worries about the draft law and called on the parliament to reject the proposed changes.

"Poland has one of the most restrictive abortion laws in Europe," Muiznieks said in a statement posted to social media. "This step would be at variance with Poland's obligations under human rights law."