"The use of dawn raids to intimidate journalists while having the police enter the premises of media organizations sends a chilling message to the rest of society that criticism will not be tolerated," the global organisations of the world's press said in a statement.
"Given Turkey's record of imprisoning journalists, we are deeply concerned that many of those arrested could face lengthy prison terms," the statement said.
WAN-IFRA and WEF, which represent 18,000 newspapers, 15,000 online sites and more than 3,000 companies in 120 countries, called on President Recep Tayyip Erdogan to ensure that the government respects press freedom and stop its targeting of news media.
Police attempted to raid the offices of the Zaman daily but were repelled by protesters who had gathered to support the newspaper and vocally defend a free press. The paper's editor-in-chief, Ekram Dumanli, challenged the police to arrest him and was later detained, along with Hidayet Karaca, head of the Samanyolu Media Group. Also arrested were some two-dozen journalists, producers, scriptwriters, directors, police officers and two former police chiefs.
All are accused of forming and belonging to an illegal organization with close ties to US-based Islamic cleric Fethullah Gülen, a former ally but now a leading critic of President Erdogan. The arrests appear to be in connection with a year-long campaign against Gülen and his alleged supporters following a corruption scandal that implicated the government and the President's entourage. Authorities maintain that the allegations were an attempt to seize power by Erdogan's critics.