Turkey has arrested more than a dozen high-profile activists and academics as part of its investigation into a jailed philanthropist accused of seeking to topple the government of President Recep Tayyip Erdogan, a case that has drawn criticism from the EU.
The state-run Anadolu news agency said police had detained 13 people and were seeking seven more as part of a probe into Osman Kavala, the founder of a Turkish civil society group called Anadolu Kultur who has been held in solitary confinement since October 2017 without an indictment.
Anadolu Kultur was founded in 2002 to promote understanding through cultural and artistic exchanges.
However, the group is suspected of trying to "overthrow the government or prevent it from fulfilling its duties by spreading chaos and confusion" in connection with the mass demonstrations in Istanbul's Gezi Park in 2013, the biggest protests during Mr Erdogan's presidency. Pro-government media have said Mr Kavala was also being held for allegedly aiding an Islamic sect that Turkey blames for instigating a failed military coup in 2016.
The European Parliament this week called on the European Commission to formally suspend Turkey's stalled accession talks, citing Mr Kavala's arrest in a long list of human rights abuses. The European Court of Human Rights this year agreed to hear Mr Kavala's application.
Those held in the latest wave of arrests on Friday included Turgut Tarhanli, dean of the law faculty at Istanbul Bilgi University, and Betul Tanbay, of the Bogazici University and vice-president of the European Mathematical Society.
Cigdem Mater, an award winning film-maker, and Hakan Altinay, a researcher for the Brookings Institution and Yale University, were also arrested. Mr Altinay previously chaired the Turkish board of the Open Society Foundation, founded by billionaire George Soros, who has been targeted in rightwing conspiracy theories. Mr Erdogan has described Mr Kavala as "Turkey's Soros".
The arrests highlight the perils activists and academics face since Mr Erdogan launched a sweeping crackdown following the abortive coup. Scholars at Risk, a US-based network of academics, have said that more than 880 university professors, students and staff have faced imprisonment, prosecution, dismissals and travel restrictions in Turkey.