Turkiye warned on Friday against “illegal” calls from the main opposition for street protests over the detention of Istanbul’s mayor Ekrem Imamoglu, after some of the country’s biggest shows of civil disobedience in more than a decade.

The warning from President Tayyip Erdogan’s government comes ahead of a possible weekend ruling by a court to formally arrest the mayor, which could escalate both the protests and a sharp selloff in Turkish assets.

Interior Minister Ali Yerlikaya said 53 people were detained and 16 police officers were injured in protests that began at university campuses, an Istanbul municipal headquarters and elsewhere on Thursday, despite a four-day ban on public gatherings imposed Wednesday when Imamoglu was detained.

The demonstrations triggered scattered clashes.

Imamoglu, who is Erdogan’s main political rival and leads him in some polls, was detained facing charges including graft and aiding a terrorist group. He can be held until Sunday, by which time the court must decide on his arrest.

The mayor’s main opposition Republican People’s Party (CHP) has condemned the move as politically motivated and urged people to demonstrate lawfully, while European leaders have called it democratic backsliding.

Yerlikaya and the justice minister, Yilmaz Tunc, criticised the calls for action from CHP leader Ozgur Ozel as “irresponsible”.

“Gathering and marching in protest are fundamental rights. But calling to the streets over an ongoing legal investigation is illegal and unacceptable,” Tunc said on X early on Friday.

Tunc said the “independent and unbiased judiciary” was evaluating the case. He has warned against linking Erdogan to Imamoglu’s arrest.

Demonstrations took place Thursday in Ankara, Izmir and Istanbul, as well as other provinces across the country, with police erecting barricades, blocking streets and using water cannons to disperse some crowds, especially students.

‘Theatrics’

Turkiye has dramatically curbed civil disobedience since nationwide 2013 Gezi Park protests against the government, which prompted a violent state crackdown seen as one of the main pivots toward autocracy under Erdogan’s 22-year reign.

The president on Thursday dismissed the opposition’s criticism as “theatrics” that distract from its internal mistakes.

Speaking at the main Istanbul rally late Thursday, the CHP’s Ozel responded: “Hey Erdogan, you’re most scared of the streets. We are now on the streets, in squares. Continue to be afraid.”

“While you keep the one we elected in custody, we will not sit at home,” he said before thousands of supporters.

“Mr Tayyip, you are scared and you are asking, ‘are you calling people to the streets? Are you calling people to the squares?’ Yes, yes, yes. I didn’t fill up these squares or these streets, you did.”

On Friday Ozel said bans on protests were “illegal” and called on people to demonstrate again Friday evening without “fighting or violence” in order to protect their right to vote.

His call ratcheted up pressure on the government and heightened political tension nationwide, given many of Imamoglu’s supporters had called for stronger steps and organisation from the CHP since the detention.

The move against Imamoglu, 54, a two-term mayor, comes as the CHP was set to announce him as its presidential candidate on Sunday. It has called for non-party members to vote for him in ballot boxes set up across the country, as a sign of public resistance.

No presidential vote is scheduled until 2028, and Erdogan, 71, can run again only if parliament calls an early election.

Crackdown

Imamoglu’s detention caps a months-long legal crackdown on opposition figures that critics portray as an attempt to hurt their electoral prospects and silence dissent, charges the government denies.

Turkiye’s lira and bonds have since tumbled, with Istanbul shares down 7 per cent on Friday.

The central bank hiked its overnight rate in an unscheduled meeting and on Wednesday alone spent around $10 billion in FX reserves to help stabilise the currency at around 38 to the dollar, after it plunged 12pc to an all-time low.

The economy remains weak with inflation at 39pc despite a nearly two-year effort to reverse soaring prices and currency crashes due mostly to Erdogan’s previous backing of unorthodox monetary stimulus.

In an interview Thursday, Ozel told Reuters that his party would resist any attempts to remove him and CHP officials from the municipality headquarters, where they have been staying since Imamoglu’s detention. The party would also resist any unjust replacement of Imamoglu, he said.

A government appointee could replace the mayor because of the probe charging him with aiding the outlawed Kurdistan Workers Party (PKK), deemed a terrorist organisation by Turkey and its Western allies.

His detention came a day after a university annulled his degree, which if upheld would block him from running for president under constitutional rules that require candidates to have a four-year degree.