In a re-run of events on Thursday, protesters blocked access to ministries due to be visited by troika representatives on Friday.
Officials from the European Central Bank, the European Commission and the International Monetary Fund were due to meet with Transport Minister Yiannis Ragousis at his department but dozens of anti-austerity protesters picketed the building and prevented them entering.
It was not clear if the meeting was relocated.
Civil servants protesting wage cuts and firings demonstrated outside the Finance Ministry for a second day.
Members of the Communist Party-affiliated PAME union protested outside several tax and Public Power Corporation offices.