A Turkish court jailed Istanbul Mayor Ekrem Imamoglu on Sunday pending trial, CNN affiliate CNN Turk reported, as mass protests have broken out across the country against his detention over allegations of corruption and terrorism ties.

The formal arrest of Istanbul Mayor Ekrem Imamoglu, who is expected to win his party’s presidential nomination on Sunday, escalates a standoff with the country’s opposition.

A Turkish court jailed President Recep Tayyip Erdogan’s most prominent rival, arresting him on corruption charges on Sunday, in what critics say is a major blow to democracy. Istanbul Mayor Ekrem Imamoglu who was preparing to announce his candidacy in the presidential vote for 2028,