Istanbul Mayor Ekrem Imamoglu was summoned for questioning by police on Saturday on terrorism charges, a day after he was questioned in a corruption case.
His arrest this week sparked mass protests across Turkey, with demonstrators taking to the streets in several cities to voice their discontent.
Interior Minister Ali Yerlikaya posted on social media that 343 suspects had been detained during protests in major cities on Friday evening, adding: “We will not tolerate those who seek to disrupt public order, threaten the peace and security of citizens, sow chaos and provoke.”
Cities mentioned include Istanbul, Ankara, Izmir, Adana, Antalya, Canakkale, Eskisehir, Konya and Edirne.
The mayor, a prominent opposition figure seen as President Recep Tayyip Erdogan's main rival, was arrested on Wednesday after an early morning raid on his residence over allegations of financial crimes and links to Kurdish militants.
Dozens of other influential figures, including two district mayors, were also detained.
Many see the arrest as a politically motivated attempt to eliminate a popular opposition figure and a key rival to Mr Erdogan in the upcoming presidential election, scheduled for 2028.
Government officials have rejected accusations that lawsuits against opposition figures are politically motivated and insist that Turkey's judiciary is independent.
On Friday, police questioned Mr. Imamoglu for four hours on corruption charges, during which he denied all accusations, Cumhuriyet newspaper and other sources reported.
He is expected to appear in court later Saturday for questioning by prosecutors and possible charges.
His arrest has sparked protests that have steadily grown in intensity.
Istanbul police used pepper spray, tear gas and rubber bullets on Friday to push back hundreds of protesters who tried to break through a barricade near the city's historic aqueduct, throwing flares, rocks and other objects at officers.
Police also dispersed groups that had gathered outside city hall for a third night in a row after opposition Republican People's Party leader Ozgur Ozel gave a speech in support of the mayor.
At the same time, police broke up demonstrations in Ankara, the capital, and the Aegean coastal city of Izmir, sometimes using force, television footage showed.
Thousands of people came out
Sourse: breakingnews.ie
