Riots broke out in Athens and Thessaloniki overnight, on the occasion marking the 10th anniversary since the murder of Alexandros Grigoropoulos, a teenager shot dead by a policeman in Exarchia in 2008.
One person was injured and 35 people were detained on Thursday during clashes between police and rioters in Athens.
The rioting started in Klafthmonos Square in central Athens after a school and student rally in the afternoon, while a second round of violence erupted in Exarchia after a second protest march in the evening.
.The incidents were focused mainly around Stournari Street and nearby Tositsa where protestors had set up roadblocks, with youths attacking police forces with firebombs, stones, pieces of marble and other objects.
Clashes between police and rioters were also taking place throughout the Exarchia district, with youths throwing petrol bombs and stones and police responding with use of tear gas.
Meanwhile, in Thessaloniki, a fire broke out in a metro work site on Egnatia Street during incidents in the northern Greek city that followed the march held in memory of Alexandros Grigoropoulos.
Firemen sped to the scene and quickly put out the fire that had started in a container on the site, as well as other blazes on Egnatia Street. Police arrested one individual caught in the act for participation in the ongoing incidents, by groups armed with petrol bombs that are holed up in the School of Theology.