Twelve of the 15 suspects detained over the a rampage in downtown Athens late on Thursday were freed on Friday, as police did not find any incriminating evidence.
The other three people were foreign nationals who were not involved in the rioting but remained detained because they did not hold legal residence permits.
A group of about 30 self-styled anarchists wielding clubs smashed windows in two bank branches, 11 shops in central Akadimias, Voukourestiou and Valaoritou Streets on Thursday night.
They scattered fliers and shouted slogans in support of convicted November 17 terrorist Dimitris Koufodinas, who is on hunger strike in protest at prison authorities’ refusal to grant him a leave.
According to reports, the vandals had been gathered at the campus of Athens Law School before heading out on their rampage.