Turkey's Prime Minister Recep Tayyip Erdogan has called a high-level corruption crackdown on business and government circles as a "dirty operation" to smear his administration and undermine the country's progress.
The government started to make comprehensive revisions in the Turkish police force on Wednesday, a day after the detentions, in a move widely perceived as Ankara's response to the corruption investigation.
Turkish media reports said that tens of high-level police commissioners have been sacked following the raids related to the probe that led to detention of at least 51 people including the sons of three cabinet ministers as well as senior bureaucrats and prominent businessmen. Nine of the detained have been released late on Wednesday.
As we fight to make Turkey in the top 10 countries of the world... some are engaged in an effort to halt our fast growth.
According to the reports, at least 11 senior police officers in Istanbul, Turkey's largest city, 19 in the capital of Ankara and three in the Aegean city of Izmir were removed their posts and some of them have already been assigned to passive posts outside these two cities.
The comprehensive changes in the Turkish police have also spread to cities of Bursa, Kayseri, Trabzon and Kocaeli, reports said, adding that the number of police officers removed from their positions is steadily rising.
Those detained in relation to the investigation on Tuesday include the sons of Interior Minister Muammer Guler, Economy Minister Zafer Caglayan and Environment Minister Erdogan Bayraktar.
Various well-known businessmen and bureaucrats were also detained including Suleyman Aslan, the chief executive of Turkish state bank Halkbank, Mustafa Demirand, the mayor of Istanbul district Faith, and Ali Agaoglu, a renowned construction tycoon.
The suspects are accused of accepting and facilitating bribes to secure construction permits for protected areas, the Turkish media reported.
Some reports on Wednesday also claimed that $4.5m have been seized at Aslan's house.
'State within state'
Speaking at a press conference in Ankara on Wednesday, Erdogan said those behind the investigation were trying to form a "state within a state", an apparent reference to the movement of United States-based Turkish cleric Fethullah Gulen, whose followers are influential in Turkey's police and judiciary.
Any minute he [Interior Minister Guler] stays on duty bleeds [Turkey's] democracy.
"We will not allow political plotting," he said, adding: "As we fight to make Turkey in the top 10 countries of the world... some are engaged in an effort to halt our fast growth. There are those abroad... and there are extensions of them within our country... Right now a very dirty operation is going on."
Political tensions are running high in Turkey ahead of a series of elections starting next year that will pose a key test for Erdogan after anti-government protests in June.
The opposition called on the government and particularly Interior Minister Guler to resign, saying that him staying at his seat would "shadow the soundness of the investigation".
"Any minute he stays on duty bleeds [Turkey's] democracy. This opens [the rule of] law to question," Haluk Koc, the deputy chairman of main opposition Republican People Party's (CHP) told reporters on Wednesday.
Kemal Kilicdaroglu, the CHP leader, said his party was "worried about a political intervention into the case" following sacking of senior police officers.
Many analysts linked the investigation to the recent rift between Fethullah Gulen and Erdogan's ruling Justice and Development Party (AKP).
The tensions between the two fronts arose after the government's plans to abolish private prep schools that prepare students for the Turkish central university exam. Gulen owns a large network of such schools.
Gulen supported Erdogan's AKP since 2002, but the bitter row between the two in recent weeks risks fracturing their support base before local and presidential elections next year.
The cleric, 72, has been living in exile in the US since 1999 to escape charges of plotting against the secular state but his movement still wields considerable influence within the status apparatus in Turkey including the police and the judiciary.
Source: Al Jazeera and agencies