Turkish police on Tuesday detained 35 suspects including high-ranking bureaucrats and police officers as part of a probe into supporters of a US-based cleric accused of plotting to bring down President Recep Tayyip Erdogan, local media reported.
Police raided several addresses in the western coastal city of Izmir, the private Dogan news agency reported.
The operation comes just after Erdogan's Justice and Development Party (AKP) swept back to power by winning almost half of the vote in Sunday's election.
A strengthened AKP government is expected to speed up efforts to clean the state of exiled Turkish cleric Fethullah Gulen's loyalists.
A former ally of Erdogan turned arch-enemy who lives in the United States, Gulen is charged with "running a terrorist group" which launched a probe into the president's inner circle in 2013.
He is due to go on trial in absentia in January.
Erdogan accuses Gulen of trying to topple him by persuading allies in Turkey's police force and judiciary to launch a vast probe into government corruption in December 2013, which led to the resignation of four ministers.
Turkish authorities responded by purging both the police force and judiciary of pro-Gulen elements and arresting news editors and businessmen.
The movement had supported the Islamic-rooted AKP when it came to power in 2002 but the relationship between the cleric and president degenerated as Erdogan became increasingly worried about Gulen's bid for power.