Turkey's biggest newspaper, Zaman, has condemned its takeover by the authorities in a defiant last edition published just before police raided it.
Saturday's edition said Turkey's press had experienced "one of the darkest days in its history".
Police raided Zaman's Istanbul offices hours after a court ruling placed it under state control, but managers were still able to get the edition to print.
Police later fired tear gas to disperse Zaman supporters.
Water cannon was also used as about 500 people gathered in front of Zaman's headquarters on Saturday. They chanted "Free press cannot be silenced!"
A number of the journalists returned to work, but some of them tweeted that:
- they had lost access to internal servers and were not able to file articles
- they were not able to access their email accounts
- the newspaper's editor-in-chief Abdulhamit Bilici and a leading columnist had been fired
One reporter, Abdullah Bozturk, said attempts were also under way to wipe the newspaper's entire online archive.
The European Union's response has been to issue weak statements of concern, the BBC's Mark Lowen says.
It is accused of acting softly on Turkey as it needs the country's support in managing the refugee crisis.
The paper is closely linked to the Hizmet movement of influential US-based cleric Fethullah Gulen, which Turkey says is a "terrorist" group aiming to overthrow President Recep Tayyip Erdogan's government.
Mr Gulen was once an ally of Mr Erdogan but the two fell out. Many Hizmet supporters have been arrested.
The court ruled on Friday that Zaman, which has a circulation of some 650,000, should now be run by administrators. No explanation was given.
Turkish Prime Minister Ahmet Davutoglu said the move was "legal, not political".
"It is out of the question for neither me nor any of my colleagues to interfere in this process," he said in a television interview.
The government in Ankara has come under increasing international criticism over its treatment of journalists.
The EU's diplomatic service said that Turkey "needs to respect and promote high democratic standards and practices, including freedom of the media", while the US described the move as "troubling".
The Saturday edition of the newspaper was printed before the government-backed administrators had taken control.
"The Constitution is suspended," a headline in large font on a black background reads on the front page.
"The Turkish press has experienced one of the darkest days in its history," the paper adds.
"Turkey's mass circulation newspaper was seized despite Prime Minister Ahmet Davutoglu's assurance that 'free press is our red line.'"
The English-language edition echoed its sister paper with the headline: "Shameful day for free press in Turkey."
Police entered the building in Istanbul late on Friday, firing tear gas at protesters who had gathered outside.
Hundreds of Zaman supporters defied the police. One held a placard saying: "We will fight for a free press."
"I believe that free media will continue even if we have to write on the walls," Zaman's editor-in-chief Abdulhamit Bilici said shortly before the raid on Friday. "I don't think it is possible to silence media in the digital age."
He was speaking to the Cihan news agency, which was also affected by the court order.
Freedom of the press in Turkey
- Turkey ranks 149th among the 180 countries in the Reporters Without Borders' World Press Freedom Index 2015
- Media organisations in Turkey say that more than 30 journalists are currently behind bars; most are of Kurdish origin
- The government argues journalism in Turkey is among the most free in the world