Self-styled anarchists resumed their violent activity on Friday morning in Athens attacking stores and a post office on Patission Street in central Athens.
A number of people who had their faces covered created damage to a series of stores and a Hellenic Post branch within a few dozen meters from the building of the Athens University of Economics and Business.
Earlier on Friday unknown assailants had gas canisters explode outside a Culture Ministry building at Karytsi Square, near Syntagma in Athens city center.
It follows a night of tension in Athens, with self-styled anarchists attacking riot police with Molotov cocktails at Tositsa Street.
These incidents forms part of nationwide protests against the holding of a suspected terrorist at a Larissa prison. Constantinos Giagtzoglou is on hunger strike asking for his transfer back to Korydallos high-security prison in Piraeus. His application is examined on Friday. He is accused of sending a letter bomb to former prime minister Lucas Papademos.