The demonstration on Tuesday was meant to mark the anniversary of Abdullah Ocalan's capture in Kenya on 15 February 1999.
"End the isolation," read banners held by a crowd of some 300 activists, referring to Ocalan's solitary confinement on a prison island in northwestern Turkey.
Police moved on the demonstrators, using truncheons and tear gas, when they refused to disperse after reading out a press statement and demanded to also stage a march and a sit-in.
The injured included also policemen hurt by stones hurled by the crowd.
Kurdish activists have long been calling for Ocalan's transfer to an ordinary jail, but their appeals have so far fallen on deaf ears in Ankara.
The PKK campaigned for Kurdish
self-rule between 1984 and 1999
Ocalan, the leader of the outlawed Kurdistan Workers' Party (PKK), was condemned to death in June 1999, but his sentence was commuted to life in prison in 2001 following Turkey's abolition of capital punishment as part of reforms to embrace European Union norms.
The PKK waged a bloody armed campaign for Kurdish self-rule in southeast Turkey between 1984 and 1999, with the conflict claiming some 37,000 lives.
Rights of Kurds
Meanwhile, a Council of Europe panel said in Strasbourg Turkey has made some legislative progress in protecting the rights of Kurds and other minorities but lags well behind in applying those laws, .
The European Commission against Racism and Intolerance (ECRI) said in a report on Tuesday that Turkey - which last December won approval to start long-term accession talks with the European Union - continues to have "some gaps in the constitution and in criminal, civil and administrative law as regards action against racism and racial discrimination."
Kurds "encounter major problems related to the armed conflict"
European Commission against Racism and Intolerance report
Kurds, who make up an estimated 20% of the 70 million-strong population, in particular "encounter major problems related to the armed conflict" in southeast Turkey, where Kurdish separatists have been active in recent decades, it said.
The commission recommended that Turkey's laws for minorities and immigrants be strengthened, that Kurdish problems be addressed, public-awareness campaigns be launched, and a national anti-racism body to oversee the initiatives be set up.
The Council of Europe is a 46-nation organisation that includes the EU's current 25 states plus non-EU countries such as Turkey. Members are required to adhere to the council's human rights principles.