The mayor of Istanbul’s Bayrampaşa district was taken into custody early Saturday on charges including bribery, embezzlement and fraud, as Turkish authorities continued a crackdown on the country’s opposition.

Mayor Hasan Mutlu, a member of the opposition Republican People’s Party (CHP), was detained under an order issued Saturday morning for 48 individuals amid a corruption investigation into the Bayrampaşa municipality, according to public broadcaster TRT Haber. The Istanbul police reportedly raided 72 locations and detained Mutlu and several of his deputies.

The politician confirmed his detention on X. “What happened is nothing more than political operations and baseless slander,” Mutlu wrote.

Mutlu is the latest in a string of opposition officials to be arrested in recent months in a clampdown on opposition to Turkish President Recep Tayyip Erdoğan.

In August, İnan Güney, the mayor of Istanbul’s Beyoğlu district was taken into custody for alleged corruption. 

In March, Istanbul Mayor Ekrem İmamoğlu — Erdogan’s top political rival —  was sent to prison on charges of corruption and aiding a terrorist group, despite massive protests. A new trial against him began on Friday, where İmamoğlu faces charges of falsifying his university degree.

Mutlu, Güney and İmamoğlu are all members of Turkey’s largest opposition party, the social democratic CHP.