Turkish police chiefs who oversaw a wave of high-profile arrests for bribery have been sacked from their posts in Istanbul, Turkish media say.
Five police chiefs are said to have been fired in Istanbul a day after at least 52 people were picked up, including sons of cabinet ministers.
Tuesday's arrests in dawn raids shocked the political establishment.
They are being portrayed by some as an attack on Prime Minister Recep Tayyip Erdogan, in a feud with a former ally.
Fethullah Gulen, an influential Islamic scholar living in exile in the US, once backed the ruling AK Party, helping it to victory in three elections since 2002.
His followers are said to hold influential positions in institutions from the police and secret services to the judiciary and the AK Party itself.
Commentators in Turkey believe the arrests - and subsequent firings - are evidence of a new dramatic fault line in Turkish politics, one within the AK Party itself, the BBC's James Reynolds reports.
In recent months, the alliance began to come apart and in November the government discussed closing down private schools, including those run by Mr Gulen's movement, Hizmet.
In a speech after Tuesday's wave of arrests, Mr Erdogan vowed not to bow to any "threat" or "dirty alliances" aimed at creating division within the ruling party.
"Turkey is not a banana republic or a third-class tribal state," he said, speaking in the city of Konya, an AK stronghold. "Nobody inside or outside my country can stir up or trap my country."
Police silence
The five police commissioners sacked include the heads of the financial crime and organised crime units, who were both involved in the earlier arrests, the Turkish daily Hurriyet reports.
Also dismissed were the heads of the smuggling unit, the anti-terrorism branch and the public security branch, the paper says.
No immediate reason was given for their dismissals and, approached by Reuters news agency, police would not comment.
The mass arrests - according to Hurriyet, as many as 84 people were detained - were carried out as part of an inquiry into alleged bribery involving public tenders.
The sons of Interior Minister Muammer Guler, Economy Minister Zafer Caglayan and Environment Minister Erdogan Bayraktar were among those detained.
Police also raided the Ankara headquarters of one of Turkey's biggest banks, state-run lender Halkbank, and the headquarters of a large construction company owned by tycoon Ali Agaoglu.
Fethullah Gulen has been living in the US since 1999, when he was accused in Turkey of plotting against the secular state.
