Imamoglu, from the main opposition Republican People's Party (CHP), leads President Erdogan in some polls. 

He was jailed pending trial over allegations of graft on Sunday, provoking significant protests nationwide. 

A person dressed as Pikachu was witnessed attending a protest against Erdogan's Government in Antalya. 

The CHP, other opposition parties, rights groups, and Western powers have all indicated that the case against Imamoglu is a politicised effort to eliminate a potential electoral threat to Erdogan.

The government denies any influence over the judiciary and remains that the courts are independent.

The Journalists' Union of Turkey said two journalists who covered the anti-government protests in Istanbul were detained early on Friday in a separate incident. 

The CHP has called on Turks to continue protesting, saying it would organise rallies and gatherings at different locations in Istanbul and elsewhere. 

President Erdogan dismissed the protests as a "show" and warned of legal consequences for protesters.

Interior Minister Ali Yerlikaya said 1,879 people had been detained since the protests began more than a week ago, adding that courts jailed 260 pending trial.

With AAP.