Turkish authorities have detained Istanbul Mayor Ekrem Imamoglu, a key rival to President Recep Tayyip Erdogan, as part of corruption and terror investigations, according to state broadcaster TRT, citing the Istanbul Prosecutor’s Office.

Turkish President Tayyip Erdogan said on Thursday the main opposition party was seeking to cover up its own mistakes and deceive people with "theatrics", in his first comments on the detention of Istanbul's mayor.

Police arrested dozens of people, including Istanbul Mayor Ekrem Imamoglu, who was expected to be the opposition party’s presidential candidate.