TURKISH police arrested Istanbul’s mayor and several other prominent figures yesterday as part of investigations into alleged corruption and terror links. 

The move was a dramatic escalation in an ongoing government crackdown on the opposition and dissenting voices by Turkey’s authoritarian President Recep Tayyip Erdogan. 

The Anadolu Agency said prosecutors issued detention warrants for the mayor, Ekrem Imamoglu, and some 100 other people. Amongst those detained was Mr Imamoglu’s close aide Murat Ongun.

Authorities also closed several roads around Istanbul and banned demonstrations in the city for four days in an apparent effort to prevent protests following the arrest. 

NTV television reported that two Istanbul district mayors were also amongst those detained.

Critics say the crackdown is politically motivated and follows significant losses by President Erdogan’s ruling party in local elections last year.

Government officials insist that the courts operate independently and reject claims that legal actions against opposition figures are politically motivated.

The arrest came during a search of Mr Imamoglu’s home, but it was not immediately clear if police confiscated anything at the site.

A day earlier, a university in Istanbul invalidated Mr Imamoglu’s diploma, effectively disqualifying the popular opposition figure from running in the next presidential race. Having a university degree is a requirement for running in elections under Turkish law.

“We are facing great tyranny, but I want you to know that I will not be discouraged,” Mr Imamoglu said earlier in the day in a video message. 

He accused the government of “usurping the will” of the people.

Tulay Hatimogullari, the co-chairwoman of Turkey’s pro-Kurdish Peoples’ Equality and Democracy Party, condemned the detentions and called for the immediate release of all taken into custody.

She said: “The dawn raid and detention of the mayor of the country’s largest city for political motives is a disgrace that will not be forgotten for centuries. 

“This operation, which shatters faith in justice, is an attempt to redesign politics through the judiciary.”