Istanbul, Turkey (CNN) -- The sons of at least three government ministers, the head of a public bank, several bureaucrats and high-profile businessmen were detained by Turkish police Tuesday as part of a sweeping corruption probe, state-run media reported.
Analysts called the move a signal of the growing rift within Prime Minister Recep Tayyip Erdogan's ruling party ahead of local elections in the spring.
The detentions came after a two-year probe by the Istanbul Prosecutor's Office into allegations of corruption including money laundering, gold smuggling and bribery, according to the semi-official Anadolu news agency.
Police carried out dawn raids in Istanbul and Ankara, according to local media, including the headquarters of Halkbank, a public bank that was alleged to play a role in sidelining sanctions on Iran in a gold-for-oil scheme last year.
The sons of Interior Minister Muammer Guler, Economy Minister Zafer Caglayan and Environment and Urban Planning Minister Erdogan Bayraktar were detained in the raids, according to local media.
The head of a large construction company, Ali Agaoglu, was also brought in within the scope of the investigation, though the CEO of the company later told Dogan News Agency that Agaoglu was not the focus of the investigation.
Local commentators and analysts see the raids as the most public confirmation of the developing rift between Erdogan's ruling party and supporters of Fethullah Gulen, an Islamic cleric living in Pennsylvania whose loose network of followers are thought to hold key positions within the judiciary and police force.
The Hizmet Movement, the name preferred by Gulen's followers, has in the past thrown its support behind the ruling Justice and Development Party, or AKP, led by Erdogan, but the two have been publicly at odds over the last month. "It was a forced marriage and now it's an ugly divorce," said Ahmet Sik, a journalist who wrote a book on Gulen and his influence within the judiciary and the police force.
Last month, Erdogan announced that he would shut down college admission tutorial centers, a large source of revenue and recruitment opportunity for the Gulenists. On Monday, Hakan Sukur -- a former footballer and Gulen follower who was elected to parliament on the AKP party ticket -- resigned from the party, citing the government's stance on tutorial centers.
"This is all a judicial process, it would not be right for me to say anything until the outcome," Erdogan told reporters in Konya. But in a fiery speech he delivered there he said "those who are receiving the support of financial circles and media cannot change the direction of this country. Those who are supported by dark circles from inside and outside the country cannot change the direction of Turkey."
Turkey is expected to hold local elections in 2014 and many analysts see this as a test of Erdogan's grip on power after a turbulent year of unprecedented anti-government protests.