Protesting students waved flags and placards with texts such as "Resign, government!" and "Tayyip, resign!"
President Recep Tayyip Erdogan called the popular gatherings "street terror" in a speech on Tuesday, and said that the path the demonstrators had chosen was "a dead end".
Many demonstrators are masked.
We cannot express ourselves freely, says a woman to AFP, adding that she is out to "defend democracy".
Main Challenger
Özgür Özel, leader of Ekrem Imamoglu's party CHP, came to the prison where Imamoglu is being held earlier on Tuesday. Afterwards, he told reporters that he was ashamed of the government in Turkey and "the situation Turkey is being subjected to".
The Mayor of Istanbul, Imamoglu, was arrested on March 19, accused of corruption, and has been removed from office. Imamoglu is seen as the main challenger to Erdogan, who has been in power for 22 years.
In a speech to the demonstrators, Özgür Özel called for new large-scale protests on Saturday in support of the mayor and "to demand transparency, open trials, to say that we have had enough and want early elections".
The ban on demonstrations, which was introduced last week, has been extended until April 1. But it has not prevented hundreds of thousands of people from participating in street protests every day since Imamoglu's arrest.
Journalists Arrested
The gatherings have become violent in some places. According to Interior Minister Ali Yerlikaya, 1,418 people have been arrested in connection with the protests.
On Monday, several journalists were also arrested, and on Tuesday, a court announced that seven of them would be detained, including an AFP employee.
This is the first time a clearly identified journalist has been arrested while performing their duties as a result of this law on gatherings and demonstrations, says Erol Onderoglu of the freedom of expression organization Reporters Without Borders to AFP.
