A Turkish court on Tuesday ordered the formal arrest of Amnesty International’s Turkey director and five other human rights workers in a sign of what rights advocates say is the government’s growing intolerance of critical voices.

The Amnesty director, Idil Eser, was detained along with nine other human rights advocates this month during a raid on a hotel where the group was attending a workshop. Amnesty said in a statement that the rights workers “are suspected, without grounds, of ‘committing crime in the name of a terrorist organization without being a member.’ ”

Four members of the group were released on bail Tuesday but remain under investigation, Amnesty said. “This is not a legitimate prosecution,” Salil Shetty, Amnesty’s secretary general, said in a statement. “This is a politically motivated persecution that charts a frightening future for rights in Turkey.”

The government of President Recep Tayyip Erdogan has arrested more than 50,000 people in the year since an attempted coup by renegade soldiers last July, according to Justice Ministry figures. Tens of thousands of people have also been dismissed or suspended from their jobs.