Protests have erupted in Turkey after authorities detained the mayor of Istanbul, just days before he was due to be selected as a presidential candidate.
Ekrem Imamoglu, from the secular Republican People's Party (CHP), is seen as one of President Recep Tayyip Erdogan's strongest political rivals.
Prosecutors accused him of corruption and aiding a terrorist group, calling him a "criminal organisation leader suspect".
Police detained 100 people - including other politicians, journalists and businessmen - as part of the investigation, and the Istanbul governor's office has imposed four days of restrictions in the city.
Imamoglu said online "the will of the people cannot be silenced".
Protesters have taken to the streets and university campuses, and in underground stations, with crowds chanting anti-government slogans. It is a display of public anger not seen in years.
There were reports of clashes between protesters and police in Turkey's largest city forcing police to use pepper spray to disperse crowds outside Istanbul University.
Thousands of people rallied in the cold in front of the city hall, shouting: "Erdogan, dictator!" and "Imamoglu, you are not alone!"
The government has banned public gatherings in Istanbul as part of the four days of restrictions. But more protests are anticipated nationwide as opposition leaders, including Imamoglu's wife, urge people to "raise their voices".
Many streets in Istanbul have also been closed to traffic, while some metro lines have also cancelled their services.
