Turkey's main opposition leader on Sunday pledged further protests against the jailing of Mayor Ekrem Imamoglu, President Tayyip Erdogan's chief rival, aiming to sustain Turkey's biggest demonstrations in more than a decade.

Protests that erupted across Turkey following the arrest of the main challenger to President Recep Tayyip Erdogan have taken a new direction with calls for a one-day shopping boycott.

Imamoglu is being held on corruption and terrorism charges, but appeared in a special court at Silivri jail in a separate case on Friday accused of trying to intimidate Istanbul's chief prosecutor. Turkey's opposition has condemned Imamoglu's arrest as a "coup attempt against our next president" and his detention has prompted the biggest anti-Erdogan protests in more than a decade.