Riot police fired shots into the air to try and disperse a crowd of around 150 people protestors who blocked a highway in the Kadikoy district, reported the Anatolian News Agency (AA).
Thirteen demonstrators were detained as they headed for the town of Gemlik for a protest rally, organized by a nongovernmental organization of prisoners' relatives (TUHAD-FED), against the prison conditions of Öcalan, said AA.
Check points were set up around the town of Gemlik and turned away at least 60 buses from around the country.