Fresh violence has broken out in Athens after a weekend of rioting, with youths damaging shops during a demonstration.
The clashes follow the fatal shooting of 15-year-old Alexis Grigoropoulos by police on Saturday.
Two officers have been arrested over the killing.
Two separate protests had been called for this evening by the leftist Syriza party and the KKE Communists.
A group of demonstrators has been cornered by police in a square near the Athens Polytechnic university, and are reported to have been damaging neighbouring shops.
Ahead of the demos, riot police fired tear gas and staged a baton charge to break up hundreds of youth demonstrators in central Athens in the latest day of troubles sparked by the shooting.
Armed with stone shards broken from sidewalks on nearby Syntagma Square, around 300 youths had attacked riot police stationed in front of the parliament who responded with heavy discharges of tear gas.
And a police officer was injured in a firebomb attack on a police station in the city of Thessaloniki.
The officer was hospitalised with a hand injury after the attack carried out by a group of around 20 youths on a police station in Sykies, in the west of the city.
Thousands of mostly young people clashed with police and rampaged through Athens and other cities at the weekend.
Scores of businesses were destroyed, piling more pressure on the conservative government whose ratings have been hit by an economic slowdown.
As many as 34 people were injured in clashes yesterday while 20 were detained.
In Berlin, a group of more than 20 demonstrators took control of the Greek consulate in a peaceful protest over the shooting.
A spokesman for the group, who wore masks and unfurled a banner in Greek and German reading 'Killed by the state' from a consulate window, said they had accomplished their aim of disrupting consular operations and were planning to leave soon.
