Turkish police detained Istanbul’s powerful mayor, Ekrem Imamoglu, over graft and terrorism allegations, prompting outrage from the opposition which described it as a politically-motivated coup.

Imamoglu of the main opposition CHP is President Recep Erdogan’s main political rival and his detention came just days before the party was expected to name him as its candidate for the 2028 presidential election.

Widely seen as the strongest challenger to Erdogan, whose route to the presidency also included four years as Istanbul mayor, Imamoglu has seems to have been targeted by a growing number of what critics say are spurious legal investigations.

Hundreds of police joined the pre-dawn raid on his home, Imamoglu said on X before being taken away, with the authorities then briefly blocking access to social networks.

Street protests erupted despite a heavy police presence on the streets, with hundreds of officers fanning out around City Hall and closing off the central Taksim Square, as the governor banned all protests for four days. Meanwhile, the mayor’s wife, Dilek Imamoglu, called it a targeted political operation aimed at eliminating Turkey’s future president, expressing that his arrest is a direct blow to the nation, vowing that it would be fought.