Greek police arrested up to 30 protesters on Wednesday as clashes broke out around the Labour ministry in Athens.
Officials said those detained were mostly members of the Communist Party and Labour Union who had forced their way into the building.
Hundreds of people gathered after Labour Minister Giannis Vroutsis admitted in an interview that the country’s social security system was corrupt and fragmented.
Activists went on to occupy his office. Those arrested were piled into two police vans.
“They (the government) supports the interests of the oligarchy. They want to kill us. Every day they beat us. Look at the regime we have here,” protester Markos Bassioukas shouted as he was confronted by riot police.
Witnesses say two demonstrators were slightly injured during the clashes.
As well as causing record unemployment, Greece’s debt crisis continues to see the public sector cut wages.
Last week, the government used emergency powers to force striking metro workers to return to their jobs. Their walk-out left Athen’s public transport shut for nine days and the city’s roads gridlocked.