Police fired tear gas and clashed with demonstrators in Athens after some 50,000 people finished a peaceful march against cutbacks intended to fix the country's debt crisis.
The violence lasted about 30 minutes, when scores of youths hurled rocks, red paint and plastic bottles near parliament. Police said at least two people were detained, while several storefronts were vandalized.
Windows were smashed at the Finance Ministry's General Accounting Office, which has been accused by the European Union of slipshod statistics-keeping that made the financial crisis worse.
The day's protests were otherwise peaceful. Labour unions organised the protest march amid a 24-hour general strike that grounded flights, shut schools and crippled services, in a show of strength against the government.
The walkout comes as Greece is considering tougher austerity measures to ward off a financial crisis that has undermined the euro and raised fears that financial market contagion will spread to other weak economies such as Portugal, Spain and Italy. The European Union has issued a vague promise to support Greece, which has some €53 billion in debt coming due this year, but the government of Prime Minister George Papandreou has pressed for more specific guarantees to shore up market confidence.
The government says it won't need a bailout and will stick to its plans to make sharp cutbacks.
There was disruption elsewhere in Europe by workers unsettled by the threat to their jobs from the slow economy and government plans to cut back. In France, a strike by air traffic controllers disrupted flights for a second day. And in Spain, tens of thousands of demonstrators on Tuesday rallied in several cities to protest a government proposal to raise the retirement age by two years to 67.