Hundreds of protesters have gathered outside the office of an opposition newspaper in Istanbul after two journalists were jailed pending trial for reporting on alleged Turkish arms smuggling to Syria.
The demonstrators accuse the government of silencing critics and attempting to cover-up a scandal after Cumhuriyet's editor-in-chief Can Dundar and the paper's Ankara representative Erdem Gul were jailed over terror and espionage charges.
The pair were sent to a prison in Istanbul late on Thursday, accused of willingly aiding a terror organisation and revealing state secrets.
The incident comes amid deepening concerns over media freedoms in Turkey, which aspires to join the European Union.
In May, the paper published what it said were images of Turkish trucks carrying ammunition to Syrian militants.
The images reportedly date back to January 2014, when local authorities searched Syria-bound trucks, causing a stand-off with Turkish intelligence officials.
Cumhuriyet said the images were proof that Turkey was smuggling arms to rebels in Syria.
The government had initially denied the trucks were carrying arms, maintaining that the cargo consisted of humanitarian aid.
However, some officials later suggested that the trucks were in fact carrying arms or ammunition destined to Turkmen in Syria.
Prosecutors launched an investigation into the journalists after President Recep Tayyip Erdogan filed a criminal complaint.
Crowds filled the yard and a street outside of Cumhuriyet's headquarters, chanting: "Free press cannot be silenced."
Opposition MP Baris Yarkadas said: "The government does not want any journalist to see what kind of a calamity they have involved Turkey in."
At a separate protest in Ankara, police used tear gas to break up a gathering of journalists hoping to march to Cumhuriyet's office in the city.
The US Embassy expressed concern over Mr Dundar and Mr Erdem's arrests and at the apparent pressure being exerted on Cumhuriyet.
"We hope the Turkish courts and authorities will uphold the fundamental principle of media freedom enshrined in the Turkish Constitution," the Embassy said on Twitter.
Turkey ranks 149th out of 180 countries on the Reporters Without Borders news media freedom index.
On October 17 last year 29-year-old American journalist Serena Shim reported that Isis militants and weapons were being smuggled across the Turkish border into Syria on trucks bearing the symbols of NGOs like the "World Food Organisation".
Turkish National Intelligence Organization (MİT) accused Ms Shim of 'spying'. Ms Shim said this was "probably due to some of the stories she had covered about Turkey's stance on the Islamic State of Iraq and the Levant militants in Kobane."
She later reported on air that she was "a bit frightened" by what MİT "might use against me."
Two days later Ms Shim reportedly died in car accident after her car was hit by a 'heavy vehicle'. Press TV, her employer at the time, said the death was "suspicious".
London-based political analyst Shabir Hassan Ali claimed Ms Shim had been "assassinated by the government of Turkish president Recep Tayyip Erdogan." Ali said: "Serena was hounded in a fashion by Turkish intelligence."
Sanlıurfa governor İzzettin Küçük said the claims were "completely baseless". Campaigners have called for the US to launch an investigation into the death. The US government said it does not investigate the death of American citizens abroad.
Ms Shim's sister, Fatemeh, gave an interview to Afshin Rattansi last year on the show Going Underground. That interview can be viewed above.