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

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.

Reuters, the news and media division of Thomson Reuters, is the world’s largest multimedia news provider, reaching billions of people worldwide every day. Reuters provides business, financial, national and international news to professionals via desktop terminals, the world's media organizations, industry events and directly to consumers.