A leading Kurdish lawyer and rights activist was shot dead in southeast Turkey on November 28.
The pro-Kurdish HDP Party called the murder a "planned assassination," and urged people to take to the streets in protest.
According to a Reuters witness, Turkish police fired water cannon and tear gas to disperse around 2,000 people who had gathered in Istanbul’s Taksim Square on November 28.
Witnesses say Tahir Elci was shot in the head while speaking to media in Diyarbakir, the largest city in Turkey's mainly Kurdish southeast.
A policeman also died in the exchange of fire.
Elci was facing a prison term on charges of supporting the banned Kurdistan Workers Party (PKK) after he said during a live news program that they are not a terrorist organization.
It wasn't immediately clear who was behind the attack.
Interior Minister Efkan Ala and other officials said that the attack was against police officers and that Elci died in the clashes. However the Diyarbakir Bar Association said that Elci was the intended target.