The Istanbul chief prosecutor's office has opened a probe into allegations of illicit expenditures at some public events organised by the Istanbul municipality, marking the latest legal challenge to opposition-run districts in Türkiye.
The office said late on Wednesday it would investigate "irregular spendings" to determine whether the public experienced financial harm, without elaborating.
The Ankara chief prosecutor's office has also launched an investigation into two concerts organized by the Ankara municipality on Republic Day celebrations on Oct. 29.
The municipalities, which are Türkiye's two largest cities and both run by the main opposition Republican People's Party (CHP), deny the allegations, according to Reuters.
Speaking at a career fair on Thursday, Istanbul Mayor Ekrem Imamoglu - who is seen as a potential future challenger to President Tayyip Erdogan - said the probes amounted to "reputation assassination".
Late last month the CHP mayor of Istanbul's Esenyurt district was arrested and accused of belonging to the outlawed Kurdistan Workers' Party (PKK), charges he and his party reject.
Since then, the interior ministry dismissed and replaced elected mayors from the pro-Kurdish DEM party in some southeastern cities for alleged ties to militants, charges they and their party also deny.