The demonstration was one of the largest in several weeks, and occurred simultaneously as Turkey's largest party, the Republican People's Party (CHP), tries to rekindle the spark in public opinion to get him released.
Our struggle is the struggle for democracy, for freedom, said CHP leader Özgür Özel, on site at the demonstration.
Ekrem Imamoglu has, since he was arrested on corruption charges on March 19, become a figurehead for the opposition's campaign against the government. He was seen as the biggest rival to the long-time President Recep Tayyip Erdogan, but the arrest may prevent him from running in the presidential election. Imamoglu strongly denies all corruption charges.
In the days following his arrest, tens of thousands of people participated in almost daily protests, but the number has decreased in recent weeks.
