Turkish riot police on Friday clashed with demonstrators protesting for the third night in a row over the arrest of Istanbul's mayor, who is a political rival of President Recep Tayyip Erdogan.

Riot officers fired rubber bullets and pepper spray at demonstrators in Istanbul, while members of the crowd threw lit flares. In the western city of Izmir, police used tear gas and water cannon to disperse protesters.

In Istanbul, people chanted slogans such as "government, resign!"

Interior Minister Ali Yerlikaya said on social media that about 97 people were arrested at demonstrations on Friday night.

Istanbul Mayor Ekrem Imamoglu was arrested early on Wednesday in a raid on his residence over alleged links to corruption and terror.

Imamoglu's arrest came just days ahead of his expected nomination as presidential candidate for the opposition Republican People's Party (CHP).

What is behind the protests?

His supporters say the arrest was a politically motivated attempt to remove a popular challenger to Erdogan's more than two decades of rule. Presidential elections in Turkey are slated for 2028, but Erdogan will only be able to run again if a constitutional amendment is passed or if early elections are called.

"I invite tens of thousands, hundreds of thousands, and millions to peacefully demonstrate, express our democratic reaction, and exercise our constitutional rights," CHP leader Ozgur Ozel said Friday

Thousands of people have protested in Turkish cities since Imamoglu's arrest. In Istanbul, Ankara and Izmir, clashes erupted between police and protesters. In response, authorities have announced a five-day ban on demonstrations.

"To those who say that calling people to the streets is irresponsible, I say this: We are not the ones filling these streets and squares. It is your lawlessness and injustices that have brought people out," said opposition leader Ozel.

Turkish media, including the Cumhuriyet newspaper, reported that police began questioning Imamoglu on Friday afternoon. He is due to appear in court on Saturday.

How has Erdogan responded?

On Friday, President Erdogan said in a speech that authorities "would not allow public order to be damaged," and vowed not to "give in to vandalism or street terrorism."

Imamoglu's arrest is part of a monthslong crackdown on Turkey's opposition.

According to the prosecutors, Imamoglu is accused of misusing his position for financial gain.

In another investigation, Imamoglu is accused of helping the Kurdistan Workers' Party (PKK), considered a terrorist organization by Turkey, the United States and other countries, by allegedly forming an alliance with Kurdish groups for the Istanbul municipal elections.

Other arrests were also made, including two Istanbul district mayors.

Turkey's government has rejected claims of politically motivated legal actions against the opposition, insisting instead that courts operate independently.

However, Amnesty International said Imamoglu's arrest marked an escalation in an ongoing attack on Erdogan's rivals.

"While the weaponization of vague anti-terrorism allegations to detain and prosecute opponents is not new, these latest detentions and associated restrictions represent an alarming intensification of the targeting of real or perceived critics," said Dinushika Dissanayake, Amnesty's deputy director for Europe.

Edited by: Sean Sinico