Thousands of Greek anarchists marched through central Athens to protest about the arrest of nearly 92 people who tried to reoccupy a long-term squat evacuated by police last week.
The crowd, estimated at 3,000 by police and 8,000 by organisers, marched to the Athens law courts where the squatters were arraigned.
Police started to disperse when authorities began to release the arraigned individuals.
All 92 have been provisionally released and a later court date will be set, where they will appear on charges of trespassing on public property.
Unusually for an anarchist march, it ended virtually without incident, despite the close presence of riot police.
Earlier, police were seen at subway station entrances quietly searching, and apprehending individuals under suspicion of carrying rocks, batons and other projectiles.
The Greek parliament approved a series of unpopular tax rises to increase government income, one of the main conditions to qualify for continued aid from the ECB/EU/IMF Troika.
In a late-night sitting, a comfortable majority of politicians voted for the legislation, which the opposition said was another assault on Greece's struggling middle class.
The legislation scraps many tax exemptions, raises tax rates on property and corporate profits, and imposes a capital gains tax on share sales.
It hoped the measures will generate about €2.5bn in additional revenue in 2013 and 2014.
Greek Finance Minister Yannis Stournaras said: "It is a bill of fiscal necessity and responsibility, required for us to get our next bailout tranche."
The tax reform is part of an overall €13.5bn austerity package that Greece passed in November to qualify for further bailout funds from its European Union and International Monetary Fund lenders and avert bankruptcy.
Passing the bill in parliament was one of the conditions Greece had to fulfil to get €14.7bn in additional rescue loans by the end of March on top of a €34.3bn sum the lenders unlocked last month.