Turkish novelist Asli Erdogan, who was arrested in August, speaks to the media after her release from Silivri prison outside Istanbul, late Thursday. (AP/AP)

Police on Thursday detained a prominent investigative journalist for questioning over social-media postings, while a novelist and eight of her former colleagues at a now-defunct newspaper went on trial on terrorism-related charges.

Ahmet Sik, a strong government critic, was detained in Istanbul on suspicion that he “denigrated” the Turkish state, its military and police, and engaged in “terrorist propaganda” on Twitter, according to the state-run Anadolu news agency. The journalist tweeted as he was being taken away: “I’m being taken before a prosecutor for a tweet.”

Meanwhile, in Istanbul, the ­trial opened for novelist Asli Erdogan, writer Necmiye Alpay and seven other editors or senior employees of the pro-Kurdish newspaper Ozgur Gundem. They are accused of membership in the outlawed Kurdistan Workers’ Party, or PKK, of threatening Turkey’s unity and of engaging in terrorist propaganda. They were arrested for their connection to the newspaper, which was closed down in October and which authorities accused of being a mouthpiece of the PKK.

The defendants have denied the charges. They could face life terms in prison if convicted.

“I have never taken orders from anyone. I am just a writer,” the Haber Turk newspaper quoted Erdogan — who is not related to President Recep Tayyip Erdogan — as telling the court.

The court later decided to release Erdogan, Alpay and editor Zana Bilir Kaya from jail, pending the outcome of the trial.

Arrests and prosecutions of writers and journalists have added to concerns about the deteriorating state of rights and freedoms in Turkey. Asli Erdogan’s arrest in August also increased fears that the government was using emergency powers meant to deal with the perpetrators of an attempted military coup in July to go after all government critics.

Since the coup attempt, Turkish authorities have arrested 1,656 people for allegedly supporting terrorist organizations or insulting officials on social media and are investigating 10,000 more people, according to government figures.

“As we come here to watch the trial of Asli Erdogan, Necmiye Alpay, Inan Kizilkaya and other journalist friends, we have learned that another journalist friend of ours, Ahmet Sik, has been taken away,” opposition legislator Baris Yarkadas told reporters outside the Istanbul courthouse.

“Even though we woke with the hope that Asli Erdogan, Necmiye Alpay, Inan Kizilkaya and other journalist friends will find freedom,” he said, “we are still seeing journalists being targeted, apprehended and intimidated.”