Turkish authorities have issued 47 arrest warrants for municipal officials and staff in Istanbul, whose mayor Ekrem Imamoglu – the main political rival of President Recep Tayyip Erdogan – has been in prison since March.

The warrants were issued on the basis of “four separate corruption investigations focused on Istanbul,” the Anadolu Agency reported, without revealing how many people had actually been detained.

Imamoglu's arrest on March 19 sparked the biggest protests in Turkey in decades.

Police detained nearly 70 people in the ensuing crackdown on alleged corruption in Istanbul's city hall, including Imamoglu's personal secretary and his bodyguard.

The latest orders are directed against a former opposition MP and five district mayors in Istanbul.

Private television station Halk, considered close to the opposition party to which Imamoglu belongs, reported that nine district mayors out of a total of 39 are in custody. | BGNES