March 24 (UPI) -- A Turkish court formally jailed Istanbul Mayor Ekrem Imamoglu, President Recep Tayyip Erdogan's main political opponent, prompting thousands Sunday night to take to the streets across the country in protest.
A court arrested the secularist Imamoglu on corruption charges and removed him from office, Politico reported. He has been in jail since Wednesday and faces corruption charges and allegations of aiding terrorist groups. Opposition leaders have described his detention as a coup.
The court order came on the same day that the Republican People's Party was to vote for its presidential candidate -- a race in which Imamoglu was the sole candidate.
Despite his arrest, some 15 million people cast ballots on Sunday.
"Today, Türkiye woke up to a profound betrayal," Imamoglu said on X. "The ongoing judicial process is far from being fair -- it is an execution without trial. I invite our nation to fight for their rights. This fight is crucial for the future of our nation and our children."
In response to his call, people took to the streets. BBC reported that crowds had gathered near Istanbul's city hall Sunday evening for a fifth night, which were initially sparked by Imamoglu's Wednesday arrest.
Police have arrested at least 660 protesters, including 323 on Saturday, amid the nearly week of unrest. Meanwhile, X's Global Government Affairs department said it has received multiple Turkish court orders to block more than 700 accounts of news organizations, journalists, political figures, students and others in Turkey.
X's objected to the orders, it said.
"Providing a platform committed to defending everyone's right to free speech is paramount at X, and we believe this decision from the Turkish government is not only unlawful, it hinders the millions of Turkish users from news and political discourse in their country.
"X will always defend freedom of speech everywhere we operate."
Imamoglu is widely seen as Erdogan's primary challenger for president. The next election is set to be held by 2028.
"You will be defeated one way or another," Imamoglu told Erdogan on X.
"I stand tall, I will never bow."