Greek police have fired tear gas to disperse anarchists throwing petrol bombs near parliament in a protest against austerity measures in Athens.
Dozens were arrested during the one-day strike on Wednesday against planned spending cuts of €11.5 billion. It was the first union-led action since a conservative-led coalition came to power in June this year.
An estimated 50,000 people joined the protests, including doctors, teachers, tax workers, ferry operators and air traffic controllers, the BBC reports.
Banks and historic sites in Athens remained shut, with many shopkeepers expected to close up early so they could attend demonstrations. Schools and government services also closed down, though buses were still running, reportedly to help ferry people to the protests.
The protest follows a series of demonstrations in Spain and Portugal, which are also facing stringent austerity measures.
The savings are a pre-condition to Greece receiving its next tranche of bailout funds, without which the country could face bankruptcy in weeks.
The country needs the next €31 billion instalment of its international bailout, but with record unemployment and a third of Greeks pushed below the poverty line, there is strong resistance to further cuts.
The government of conservative Prime Minister Antonis Samaras is proposing to save money by slashing pensions and raising the retirement age to 67.
But it has also urged the troika representing Greece's lenders - the European Commission, the European Central Bank, and the International Monetary Fund - to give it an extra two years to push through the austerity programme.
On Tuesday, Finance Minister Yannis Stournaras put a price on that delay for the first time - saying it would in effect cost as much as €15 billion.
In May 2010, Greece was given a €110 billion bailout package and a further €130 billion in October last year, backed by the IMF and the other 16 euro nations.
Greece needs the new money to make repayments on its debt burden. A default could result in the country leaving the euro.