Greek protesters clash with police during a rally to mark the eighth anniversary of the death of a Greek teen by police fire, in central Athens, capital of Greece, on Dec. 6, 2016. A series of rallies organized by student unions, left-wing parties and anti-establishment groups in the center of Athens on Tuesday to commemorate the 2008 death of a Greek teen by police fire, ended in clashes with anti-riot forces. (Xinhua/Marios Lolos)