WARSAW (BLOOMBERG) - Police used tear gas on protesters after Poland's top court ruled to further tighten one of Europe's strictest abortion laws, triggering impromptu demonstrations throughout the country.

In the capital, police gassed a crowd near the residence of ruling party chief Jaroslaw Kaczynski, the architect of Poland's nationalist remake over the past five years.

The court, dominated by judges appointed by the Law & Justice party, said a 27-year-old law allowing the termination of pregnancies due to damaged foetuses was unconstitutional.

"The Tribunal is doing its work," Mr Radoslaw Fogiel, a spokesman for Law & Justice, told private television TVN24 on Friday (Oct 23).

Police said that protesters threw rocks and eggs at the police, forcing the authorities to use tear gas.

The Constitutional Tribunal ruled in favour of parliamentarians from the conservative political movement who contested the law.

Human rights groups and opposition lawmakers have slammed the challenge, saying it is part of a half-decade-long assault against women's rights that included the government's attempt to ban abortions outright in 2016.

That initiative was abandoned by Law & Justice after Polish women took to the streets in anti-government protests.

Activists demonstrated again on Wednesday dressed as characters from the Handmaid's Tale, a dystopian novel by Margaret Atwood in which women are reduced to becoming the property of men with the sole purpose of bearing children.

More than 95 per cent of legal abortions in the EU's largest eastern member are performed due to damaged foetuses, according to the Nationwide Women Strike group, which organised the protest.

Law & Justice, which has vowed to return Poland to its "traditional Catholic" roots, has rejected the EU's liberal, multicultural values, clashing with its partners in the bloc over issues from gay rights to the rule of law.