Turkish riot police blasted opposition protesters with water cannons, tear gas and plastic bullets in Istanbul on Friday in scenes reminiscent of the summer's mass anti-government demonstrations.
Some of the protesters threw rocks and firecrackers at police, shouting, "Catch the thief!" in reference to a widening corruption scandal gripping Prime Minister Recep Tayyip Erdogan's government.
Similar protests were held in Ankara and the city of Izmir, but there were no immediate reports of violence.
Thousands of Erdogan backers, meanwhile, gathered at other spots showing their support for the embattled Erdogan.
A Turkish high court on Friday blocked the government from changing the rules on how corruption investigations are initiated, dealing another blow to Erdogan's government.
Probe over alleged illicit money transfers to Iran
Twenty-four people, including the sons of two former government ministers and the head of the state-owned financial institution, Halkbank, have been arrested on bribery charges.
Media reports say the probe is over alleged illicit money transfers to Iran and bribery for construction projects.
Erdodan was forced to reshuffle his government this week after the three ministers, whose sons were detained for questioning as part of the corruption and bribery probe, resigned. Erdogan says the probe is part of a wider conspiracy aimed at bringing his government down.
But his government has also removed police officers from posts and changed police regulations to ensure that corruption investigations are initiated by top police and judicial officials — some of whom are believed to be close to Erdogan. Critics have accused Erdogan of trying to stifle the investigation.
The High Administrative Court ruled Friday that the government revert to previous protocols on investigations pending further deliberations on the issue — a case that was prompted by complaints by Turkey's bar association.
Before Erdodan's government changed the regulations, prosecutors could launch investigations and order police to carry out detentions without seeking approval from superiors.
Asked to comment on the court's move, Erdogan said the government would do "whatever is necessary" but did not elaborate.
Earlier, he verbally attacked a prosecutor involved in the investigation, calling him a "disgrace" and accusing him of smearing innocent people. Some Turkish media reported that the prosecutor, who has said he was being prevented from expanding the corruption probe, wanted to summon Erdogan's son for questioning.
The prosecutor, Muammer Akkas, complained that police officers had not carried out orders for another wave of arrests.
In a written statement he distributed to reporters outside the courthouse late Thursday, he said that the chief prosecutor and police were hampering his probe.
Istanbul's chief prosecutor, Turan Colakkadi, later removed Akkas from the case for allegedly leaking information to the media, and said Akkas was carrying out "random investigations."
Aydinlik newspaper and its sister television station both published on their websites what they said was a copy of the prosecutors summons for Erdogan's son, Bilal, to testify as a "suspect" in the investigation. According to the document, the prosecutor would have questioned him on Jan. 2 on suspicion of "forming a criminal gang."
There was no immediate government statement disputing the authenticity of the document, which was also printed in Cumhuriyet newspaper.
Akkas could not be reached for comment or to verify the document while officials at the prosecutors' office refused comment.
Erdogan said earlier this week that he believed he was the target of the corruption probe, maintaining that there were efforts to get to him through his son and through an educational foundation, of which Bilal is a board member. He also said that the efforts would fail.
The foundation, TURGEV, which is involved in the building and running of student residences, refused to comment.
Erdogan repeated claims of a foreign conspiracy to destabilize Turkey and its economy in three separate speeches on Friday and slammed the prosecutor.
"A prosecutor who distributes press releases to journalists outside a courthouse is a disgrace to the judiciary," Erdogan said.
"How can you smear innocent people?" he said.
Government accused of protecting 'thieves'
Earlier, three legislators from Erdogan's party, who have been critical of the government's handling of the scandal, resigned over what they said was the government's pressure on the judiciary.
The leader of the opposition also accused the government of protecting "thieves."
"We have entered an era where the thieves are being protected and prosecutors who are going after the thieves are rendered ineffective," said Kemal Kilicdaroglu, the leader of Turkey's main opposition Republican People's Party.
Erdogan vowed to fight the graft allegations.
"We will go if the people tell us to go, but we will ignore those who tell us to go while the people tell us to stay," Erdogan said in Sakarya.
The Turkish currency continued to plunge over the turmoil with the lira reaching new lows against the euro and the dollar.
The military meanwhile, said in a statement that it would not be dragged into politics amid the scandal.
The statement came after one of Erdogan's advisers raised the possibility in a regular column published in Star newspaper that the scandal may be a plot to trigger a coup.
Turkey's military has staged three military takeovers since the 1960s but has seen its powers curbed under Erdogan's decade in powe