Turkish opposition parties called for protests Thursday at what they said was the politically-motivated arrest of an opposition mayor for alleged links to the banned Kurdish PKK militant group.
Several hundred protestors rallied on Wednesday evening outside an Istanbul court where Ahmet Ozer, mayor of the Istanbul district of Esenyurt, was charged several hours after being arrested.
Ozer belongs to the main opposition Republican People's Party (CHP), which denounced the allegations as "baseless".
Both the CHP and DEM, the main pro-Kurdish party -- which also slammed his arrest as a "political coup" -- called demonstrators to rally at 4:00 pm (1300 GMT) outside Esenyurt town hall.
But the police shut down the area, banning any demonstrations there, prompting organisers to shift the protest to a square several kilometres (miles) away.
The interior ministry said Ozer was arrested for "membership of the PKK terror organisation" and confirmed appointing Istanbul's deputy governor to replace him.
The PKK, which since 1984 has waged a decades-long insurgency against the Turkish state that has killed thousands, is blacklisted as a terror organisation by Turkey and its Western allies.
But Ozer denied the charges when he appeared in court on Wednesday evening, the private NTV television said.
- 'An undeniably political dimension' -
Ankara's opposition CHP mayor Mansur Yavas said there was an "undeniably political dimension" to Ozer's arrest, writing on X that the "vague and abstract charges" against him raised concerns about "democracy and the rule of law".
CHP leader Ozgur Ozel said the arrest was "based on abstract allegations and statements in a book (Ozer) wrote years ago" and vowed to put up "the strongest possible response".
A university professor, Ozer was elected in March when opposition candidates won in numerous towns and cities across Turkey, including Istanbul.
He is known for being close to Ekrem Imamoglu, Istanbul's powerful opposition mayor who is a major figure within CHP and likely to run as a candidate in the 2028 presidential election.
Imamoglu was at Wednesday night's protest.
The Turkish government has removed dozens of elected Kurdish mayors and replaced them with its own trustees.
Six months ago, the election authority removed the DEM party's elected mayor in the eastern city of Van, sparking furious protests when he was replaced by the losing candidate from President Tayyip Recep Erdogan's AKP party.
As a result of the backlash, the winning candidate was later reinstated.