Turkey has pulled out of an international accord designed to protect women from domestic violence.
President Recep Tayyip Erdogan has annulled Turkey's ratification of the Istanbul Convention, 10 years after it was the first country to sign the landmark European treaty.
No reason was provided for the withdrawal but top government officials said Turkey's domestic law would protect women's rights instead.
Hundreds of women gathered at demonstrations across Turkey on Saturday to protest the move.
Hatice Yolcu, a student in Istanbul who joined other women in waving purple protest flags, said: "Every day we wake up to news of femicide.
"The death never ends. Women die. Nothing happens to men."
Bearing the name of Turkey's largest city, where the Council of Europe accord was forged, the Istanbul Convention pledges to prevent, prosecute and eliminate domestic violence and promote equality.
Turkey signed it in 2011 but femicide - the killing of women and girls - has surged in the country in recent years and the convention had split Mr Erdogan's Islamist-rooted AK Party, and even his family.
Last year, officials said the government was considering pulling out during a row over how to curb growing violence against women.
Marija Pejcinovic Buric, secretary-general of the 47-nation Council of Europe, called Turkey's decision "devastating".
"This move is a huge setback and all the more deplorable because it compromises the protection of women in Turkey, across Europe and beyond," she said.
Many conservatives in Turkey said the pact undermines family structures and encourages violence.
Some object to the principle of gender equality and see it as promoting homosexuality as the convention promises non-discrimination on the grounds of sexual orientation.
"Preserving our traditional social fabric" will protect the dignity of Turkish women, Vice President Fuat Oktay said on Twitter.
"For this sublime purpose, there is no need to seek the remedy outside or to imitate others."
Family, labour and social policies minister Zehra Zumrut said the constitution and current laws guarantee women's rights.
Supporters of the convention said the withdrawal will put Turkey further out of step with the EU, which it is trying to join.
Turkey does not keep official statistics on femicide but the rate roughly tripled in the last 10 years, according to a group that monitors femicide.
So far this year 78 women have been murdered or died under suspicious circumstances, it said.
World Health Organisation data shows 38% of women in Turkey are subject to violence from a partner in their lifetime, compared with 25% in Europe.