Police in Athens have fired tear gas to disperse demonstrators hurling petrol bombs and stones as a 24-hour general strike grips Greece.
The violence erupted during a rally by more than 30,000 angry workers near the Greek parliament. They object to the government's far-reaching budget cuts.
The strike paralysed public transport. More than 100 flights were cancelled.
Many schools are closed and hospitals have reduced services. Small businesses have joined in, closing many shops.
It is Greece's first major labour protest this year, as the government sticks to austerity cuts demanded under the terms of the country's international bail-out.
The Socialist government of Prime Minister George Papandreou is cutting spending and raising taxes to reduce its debt mountain.
In May last year Greece secured a 110bn-euro (£93bn; $150bn) bail-out from the European Union and International Monetary Fund.
A series of general strikes took place last year as the government embarked on an economic austerity programme that will last several years.
The deputy leader of Greece's big GSEE union, Stathis Anestis, said the government measures were "harsh and unfair".
"We are facing long-term austerity, with high unemployment and destabilising our social structure," he told the Associated Press news agency.
"What is increasing is the level of anger and desperation... If these harsh policies continue, so will we."
This year the government is making a special effort to crack down on widespread tax evasion - one of the major reasons for its revenue shortfall.
The government says it expects the economy to shrink by up to 3% this year.