Turkish police detained Istanbul's powerful mayor Ekrem Imamoglu early Wednesday as part of a corruption probe, a move his opposition CHP party slammed as a "coup".

A key figure within the CHP, Imamoglu is President Recep Tayyip Erdogan's main political rival, and his detention comes just days before he was to be named the party's candidate for the 2028 presidential election.

Widely seen as the strongest challenger to Erdogan, Imamoglu has faced a string of what critics say are politically motivated legal cases.

As reports of his detention emerged, Turkey briefly shut down access to social networks and hundreds of police surrounded City Hall and closed off Taksim Square, with the authorities banning all demonstrations for the next four days.

Even so, several hundred people gathered near the Istanbul police headquarters where Imamoglu was taken, angrily chanting "Government resign!" an AFP correspondent said.

The move also sparked chaos on financial markets, with the Turkish lira plunging to a historic low of 39 liras against the dollar and the........

© Al Monitor