Amnesty International has called for the release of its Turkey director and other activists after they were detained by police.

Idil Eser, the head of Amnesty International Turkey, was taken away on Wednesday along with activists and trainers during a “digital security and information management workshop” on Büyükada, one of the Princes’ Islands off Istanbul, the human rights organisation said in a statement.

The daily newspaper Hürriyet said a total of 12 people were arrested in a police raid on a hotel on the island, a popular retreat with Istanbul residents.

There was no immediate comment from the police or indication of why the rights activists were being held.

Salil Shetty, Amnesty International’s secretary general, said: “We are profoundly disturbed and outraged that some of Turkey’s leading human rights defenders, including the director of Amnesty International Turkey, should have been detained so blatantly without cause.”

He said they must be immediately and unconditionally released. The whereabouts of those detained were unknown.

The detentions come less than a month after Amnesty International’s Turkey chairman, Taner Kiliç, was remanded in custody on what the group described as “baseless charges” of links to Fethullah Gülen, who is accused of masterminding the failed coup on 15 July 2016. Gülen denies any involvement.

Turkey remains under a state of emergency imposed in the wake of the coup attempt aimed at ousting President Recep Tayyip Erdoğan. Critics say the emergency has been used to round up not just the alleged plotters but anyone who dares oppose the president.

Turkish officials insist that all actions are carried out within the framework of the law.

Amnesty said the seven other activists detained included Ilknur Üstün of the Women’s Coalition, lawyer Günal Kursun and Veli Acu of the Human Rights Agenda Association.

Two foreign trainers for the workshop – a German and a Swedish national – as well as the hotel owner, were also detained in the raid, it added.