Detained Istanbul Mayor Ekrem Imamoglu has denied “terrorism” charges brought against him, according to a court document seen by the Reuters news agency.

“I see today during my interrogation that I and my colleagues are faced with unimaginable accusations and slanders,” Imamoglu said Saturday in his defence during a hearing, the document showed.

Later on Saturday, Imamoglu arrived at the Caglayan courthouse, where he was to be questioned by prosecutors, a spokesman for city hall said. Imamoglu will appear in court on Sunday as a judge is expected to decide whether to jail or release him.

The mayor, a key opposition figure and potential challenger to longtime President Recep Tayyip Erdogan, was detained on Wednesday by the government for alleged corruption and “terrorism”.

His detention came four days before his Republican People’s Party (CHP) planned to name him as its 2028 presidential candidate.

Erdogan on Saturday accused the CHP’s leadership of turning the party “into an apparatus to absolve a handful of municipal robbers who have become blinded by money.”

He also accused it of “doing everything to disturb the public peace, to polarize the nation.”

Court appearance

Reporting from Ankara, Al Jazeera’s Stefanie Dekker said Imamoglu is going to be moved from police custody to judicial custody on Saturday.

“We understand he will have a health check along with 100 or so others who are charged too, and then he will be transferred to the courthouse. So he will be questioned by a prosecutor later tonight,” she said.

“Then tomorrow morning, he appears before a judge, and the judge will make a ruling on whether … he is released without charge, released pending trial or detained pending trial,” she added.

‘Feeling of being trapped’

Imamoglu’s arrest has sparked a wave of protests that have spread within 48 hours to more than two-thirds of Turkiye’s 81 provinces, even including strongholds of Erdogan’s ruling Justice and Development Party, such as the central area of Konya and Trabzon and Rize on the Black Sea.

Justice Minister Yilmaz Tunc told reporters this week that the arrests had nothing to do with the government. “Linking investigations and cases initiated by the judiciary to our President is, at best, presumptuous and inappropriate,” he said.

Erdogan’s communications directorate has also said the presidency would continue to defend him against what it called an “irrational smear campaign”.

Despite a ban on protests and a heavy police presence, huge crowds of protesters have taken to the streets.

Turkiye saw a fourth straight night of protests on Saturday.

“The feeling of being trapped – economically, socially, politically and even culturally – was already widespread,” Kemal Can, a journalist and author of numerous books on Turkish society, told the AFP news agency.

But Erdogan does still retain support in many parts of the country that trusts the government due to the country’s divisive history and current polarized environment.

Imamoglu’s arrest, Can said, had sparked a strong reaction, “especially among young people worried about their future in a country where freedoms are increasingly restricted. It’s a reaction that goes well beyond Imamoglu.”

Imamoglu commended the protests and said in a post on X on Saturday that they were aimed at protecting “democracy” as an “inspiration” to the world.

Protest crackdown

Turkish police have cracked down on protesters.

Officials said 343 people have been arrested in the demonstrations so far, which have seen hundreds of thousands of people protest in Turkiye’s biggest cities in a massive show of defiance.

On Saturday, detention warrants were issued for 94 suspects accused of posting “provocative” calls to protest and create public “panic”, the Turkish news agency Anadolu quoted the Istanbul chief public prosecutor’s office as saying.

Police carried out simultaneous raids, detaining 56 of the suspects, and are searching for the 38 others, Anadolu reported, adding that authorities have also seized illegal drugs during searches of the suspects’ homes.

The investigation against İmamoglu is part of a sweeping probe involving 106 suspects over corruption and “terror” allegations.