Critics say the arrest of Istanbul's mayor is part of a mounting crackdown by Turkey's president to silence all dissent.

Ekrem Imamoglu, the mayor of Istanbul and a popular figure, had boasted jokingly that he was the only person to have beaten Recep Tayyip Erdogan’s ruling party in three local elections

Political opposition leader and Istanbul Mayor Ekrem Imamoglu was in Turkish police custody Wednesday after he was arrested days before being chosen as the presidential candidate for the Republican People's Party.