The Turkish government has continued to tighten its grip on Zaman, the country's largest daily newspaper, firing editor-in-chief Abdülhamit Bilici and replacing him with state trustees at the request of Istanbul's Chief Public Prosecutor's office.

Employees of the country's biggest media company the Feza Media Group, which owns Zaman, arrived at the company's Istanbul offices on Saturday to find heavily-armed Turkish police checking staff IDs before allowing them to enter the building, which has been surrounded by police barricades.

The police have been standing guard since Friday evening, when a court ruled that the Feza Media Group should no longer be allowed to operate independently. The court resolved to appoint trustees to run the group's various publications, which also include Today's Zaman and the Cihan News Agency.

After the ruling, Turkish police stormed the building to enforce the court-ordered seizure. Protesters gathered outside the building on Friday evening after news of the crackdown broke, and they continued to protest on Saturday. Turkish police have attempted to disperse the crowds using tear gas and water cannons.

La police turque disperse violemment 500 manifestants rassemblés devant le journal d'opposition Zaman. (AFP/O.KOSE) — Emre Demir (@emredemirfr)March 5, 2016

A reporter from T24, a news broadcaster in Turkey, posted a picture that showed police escorting Bilici out of the building with the caption: "Don't worry brother, the future won't belong to tyrants."

Other members of newspaper's staff tweeted similar accounts of the events inside the office on Friday and Saturday.

An army of riot police inside Zaman. They threw me out. — Abdullah Ayasun (@abyasun)March 4, 2016

Abdullah Bozkurt, a correspondent for Today's Zaman, tweeted a photo on Saturday that showed Turkish police touting guns, with the caption, "We're now prisoners in our newsrooms under heavy police presence inside #Zaman building."

"I believe that free media will continue even if we have to write on the walls," Bilici told the Cihan News Agency. "I don't think it is possible to silence media in the digital age."

The move against Zaman came hours after police detained prominent businessmen over allegations of financing what prosecutors described as a "Gülenist Terror Group." Zaman is said to have a close relationship to the "Gülen movement" or "Hizmet", a social and religious movement led by Fethullah Gülen, a Turkish Islamic scholar who currently resides in the United States in self-imposed exile. Gülen is on Turkey's list of most-wanted terrorists.

Turkish President Recep Tayyip Erdogan accuses Gülen of conspiring to overthrow the government by building a network of supporters in the judiciary, police, and media. Gülen denies the charges. The two men were allies until police and prosecutors seen as sympathetic to Gülen opened a corruption probe into Erdogan's inner circle in 2013.

'I believe that free media will continue even if we have to write on the walls. I don't think it is possible to silence media in the digital age.'

Amnesty International published a damning report on the state of press freedom in Turkey last year, noting that "unprecedented steps were taken to silence media linked to investigations of the "Fethullah Gülen Terrorist Organization." In the report, Amnesty reeled off an exhaustive list of channels that were forced to go silent, newspapers that were shuttered, and journalists who were detained over the course of just one year.

"By lashing out and seeking to rein in critical voices, President Erdogan's government is steamrolling over human rights," Andrew Gardner, Amnesty's Turkey expert, said in response to the latest crackdown.

Last week, Turkey's IMC TV went silent. The outlet was the only national news channel reporting an independent view of the situation in southeastern Turkey, where ongoing clashes between government forces and members of the Kurdistan Worker's Party (PKK) have devastated the civilian population.

Also last week, Turkey's constitutional court ordered the release of two Turkish journalists detained for three months on charges of revealing state secrets. Can Dundar and Erdem Gul, both journalists for The Cumhuriyet, published a report alleging that Erdogan's government had attempted to ship arms to Islamists in Syria. The court ruled that Dundar and Gül's rights had been violated, as well as their "freedom of expression and freedom of press." They still face life sentences at their trial later this month.

Last August, VICE News journalists Mohammed Ismael Rasool, Jake Hanrahan, and Phillip Pendlebury were detained and accused of "working on behalf of a terrorist organization" while reporting on the violence in southeast Turkey. Hanrahan and Pendlebury were released in early September, but Rasool, an Iraqi, was held in a maximum security prison for over four months before he was released in January.

According to Reporters Without Borders' World Press Freedom Index in 2015, Turkey ranked 149 among 180 countries listed. The US State Department condemned Friday's takeover of Feza Media Group as "the latest in a series of troubling judicial and law enforcement actions taken by the Turkish government."

In an op-ed on the website for Today's Zaman, editorial staff wrote: "We are going through the darkest and gloomiest days in terms of freedom of the press, which is a major benchmark for democracy and the rule of law.Intellectuals, businesspeople, celebrities, civil society organizations (CSOs), media organizations and journalists are being silenced via threats and blackmail."

Human rights groups have accused the European Union of turning a blind eye to the deterioration of free speech in Turkey — along with other abuses — in the interest of maintaining good relations with Erdogan. Turkey's shared border with Syria makes it a gateway to Europe for millions of refugees fleeing war and conflict, as well as for foreign fighters traveling to Syria to join Islamist groups.

"The European Union and the United States, as Turkey's partners and allies, should not trade Turkey's support on migration and Syria for silence over the dismantling of democratic institutions," Daniel Calingaert, the executive vice president of the US-based watchdog Freedom House told the Associated Press.

Earlier this week, Donald Tusk, the president of the European Council, lauded the "good and growing cooperation" between Turkey and the EU.