ISTANBUL (AP) — Dozens of Turkish demonstrators gathered in Istanbul on Tuesday to protest the arrests of two journalists and an academic on charges of disseminating "terrorist propaganda." A fourth journalist was released after a brief detention.

Protesters chanted "a free press cannot be silenced" and "arrests, oppression cannot intimidate us." Others held up a banner that read: "Thinking cannot be jailed."

The demonstration comes a day after a Turkish court ordered the pre-trial arrest of Reporters Without Borders' Turkey representative Erol Onderoglu, journalist Ahmet Nesin and academic Sebnem Korur Fincanci.

The three had participated in a solidarity campaign in support of Ozgur Gundem, a pro-Kurdish publication subject to multiple investigations and lawsuits.

Press freedom advocates warn that freedom of expression has dramatically declined in Turkey. More than a dozen journalists are in prison, although the government insists they have been jailed for criminal activity, not journalistic work.

The state-run Anadolu Agency said Onderoglu, Nesin and Fincanci had acted as chief editors for a day for the pro-Kurdish publication and issues they edited in May and June included alleged terrorist propaganda. The news agency also said the court ordered the suspects' arrest on "strong criminal suspicion."

Reporters Without Borders condemned their arrests as "an unbelievable low for press freedom in Turkey." Human Rights Watch slammed the "spurious allegations" that led to the detention of three out of 44 participants in the solidarity campaign and urged their immediate release.

HRW Europe and Central Asia Director, Hugh Williamson, said the arrests showed that "Turkish authorities have no hesitation about targeting well-known rights defenders and journalists who have played a key role in documenting the sharp deterioration in human rights in the country."

In a separate development, a New York-based journalist who covers the United Nations for the Turkish Hurriyet daily was released Tuesday morning. Razi Canikligil was detained for almost a full day after flying into Istanbul airport with his family.

"They arrested me in front of my three boys," Canikligil told the AP. "They were very afraid."

The journalist said an arrest warrant had been issued against him over a 2014 Twitter post on a troll account, which was mistakenly attributed to him and deemed to be offensive to President Recep Tayyip Erdogan.

No charges were pressed against Canikligil and his passport was returned to him after a night in detention at Istanbul Ataturk Airport.

"Everyone was suggesting that this was government pressure to shut me down," added the journalist. "We didn't know what the issue was."

The correspondent has recently covered the trial of Reza Zarrab, an Iranian-born Turkish businessman who was arrested in Miami for attempting to evade U.S. sanctions on Tehran. Zarrab was also a suspect in a 2013 corruption scandal involving the Turkish government.

Ayse Wieting in Istanbul and Edith Lederer in New York also contributed reporting.