By Daren Butler and Humeyra Pamuk
ISTANBUL (Reuters) - Turkish police raided media outlets close to U.S.-based Muslim cleric Fethullah Gulen on Sunday and detained 23 people nationwide in operations against what President Tayyip Erdogan says is a network conspiring to topple him.
The raids on Zaman newspaper and Samanyolu television marked an escalation of Erdogan's battle against his former ally Gulen, with whom he has been in open conflict since a corruption probe targeting Erdogan's inner circle emerged a year ago.
"The free press cannot be silenced," a crowd chanted at the Istanbul offices of Zaman as its editor Ekrem Dumanli made a speech defiantly challenging police to detain him.
"The person to be detained is waiting here. Please come and get (me). I'm waiting for you here," he said.
Media reports said arrest warrants were issued for 32 people and state broadcaster TRT Haber said 23 people had been detained in raids across EU-candidate Turkey, including two former police chiefs. The chairman of Samanyolu TV, a television producer, a director and scriptwriters were among those already held.
Erdogan, his AK Party elected in 2002, introduced many democratic reforms in his first years in power and curbed army involvement in politics. NATO allies cited Turkey as an example for Muslim democracy, but more recently critics have accused Erdogan of authoritarian tendencies, increasing reversion to his Islamist roots and intolerance of dissent.
English-language Today's Zaman editor Bulent Kenes told Reuters police had shown them documentation which referred to a charge of 'forming a gang to try and seize state sovereignty'.
Main opposition CHP leader Kemal Kilicdaroglu called the operations part of a "coup process", telling reporters his party was on the side of the victims, whoever they are.
Erdogan accuses Gulen of establishing a "parallel structure" within the state through its supporters in the judiciary, police and other state institutions, as well as wielding influence through the media. The cleric denies the accusation of seeking to overthrow Erdogan's government.
Erdogan, who consolidated his power further in moving from the prime minister's office to the presidency in August, said on Friday he would pursue Gulen's Hizmet organization into their "lairs".
The graft investigation, which became public with police raids on Dec. 17 last year, led to the resignation of three ministers and prompted Erdogan to purge the state apparatus, reassigning thousands of police and hundreds of judges and prosecutors.
Erdogan has also pushed through legislation increasing government control of the judiciary, most recently a law restructuring two top courts. Prosecutors have meanwhile dropped the corruption cases. [ID:nL6N0SC4NZ]
Sunday's police raids had been expected for a several days after a widely-followed Twitter account, which has previously given advance warning of police operations, said police were set to detain some 400 people, including around 150 journalists regarded as Gulen supporters.
(Additional reporting by Humeyra Pamuk; Writing by Daren Butler, editing by John Stonestreet)