Riot police have stormed a metro train depot in Greek capital, Athens, breaking up a sit-in by striking workers.
The workers had been on the ninth successive day of strike action that has crippled the underground system.
The conservative-led government used an emergency law to threaten the strikers with arrest unless they went back to work. It was not clear if the move would lead to transport resuming.
Strikers are opposed to proposals which might see their salaries slashed.
The operation took place shortly before 04:00 local time, with around 100 riot police officers entering the depot where workers had barricaded themselves in overnight.
A police spokesman said three people were arrested and subsequently released. The area around the depot has now been cordoned off to prevent others from joining the strike.
Bus drivers and railway workers were to join the strike on Friday. Transport unions say they will continue their action, raising the possibility that some could face arrest and criminal charges, with a prison sentence of up to five years.
The government is using civil mobilization legislation, which has only been invoked nine times since the collapse of Greece’s military dictatorship in 1974.
Riot police have stormed a metro train depot in Greek capital, Athens, breaking up a sit-in by striking workers
Workers on the underground had been striking over a public sector unified wage scheme that would see their salaries reduced by up to 25%.
Public opinion is split over the issue, but with commuters facing long taxi queues as temperatures fall, the government feels that it may just get the support it needs to hold firm.
Greece has been kept solvent by huge rescue loans from its EU partners and the IMF since May 2010.
So far, the European Central Bank, International Monetary Fund, and the European Commission have pledged a total of 240 billion euros ($315 billion) in rescue loans, of which Greece has received more than two thirds.
The Greek government required the bailouts because it was struggling to meet the interest payments on its existing debts.
Under the terms of the rescue funds, Greece is having to agree to substantial spending cuts, such as redundancies and pay freezes in the public sector, and reduced pensions.
This is having a major knock-on impact on the wider Greek economy, with the unemployment rate hitting 26.8% earlier this month, the highest figure recorded in the EU.
Athens is tightening its security ahead of a visit by German Chancellor Angela Merkel, her first since the eurozone crisis erupted nearly three years ago.
Some 7,000 police officers are on duty, public gatherings are banned in certain areas of the city and protesters have been warned to “protect the peace”.
The visit comes as Greece bids to pass new cuts of 13 billion euros ($17 billion) to qualify for more bailout cash.
Analysts say Angela Merkel is regarded by many Greeks as the author of austerity.
While Germany has contributed the most money in the bailing out of Greece, its chancellor is held responsible for demanding that Greece make swingeing cuts in exchange for the financing it has received.
Analysts say Angela Merkel is regarded by many Greeks as the author of austerity
Speaking on Monday, Jean-Claude Juncker, chairman of the Eurogroup finance ministers of the eurozone, raised the pressure on Greece, calling on the government to demonstrate it could implement planned reforms “by 18 October at the latest” to qualify for the next bailout installment of 31.5 billion euros.
He was speaking as the eurozone’s new permanent fund to bail out struggling economies and banks was formally launched at the finance ministers’ meeting.
There has been growing unrest in Greece at the planned new cutbacks.
Police have banned protests on Tuesday in much of central Athens, and within a 100-metre (110-yard) radius of the route Angela Merkel’s motorcade will travel – although two planned protests elsewhere in the city will go ahead.
On Monday, public order minister Nikos Dendias appealed to protesters to “protect the peace, and above all our country’s prospects and our international image”, Reuters news agency reported.
Angela Merkel, a target for popular dissent, will be in Athens for about six hours, and will have talks with Greek Prime Minister Antonis Samaras.
The meeting is a gamble.
If there is chaos on the streets, it will only underline for the German public that Greece is a lost cause.
But Angela Merkel’s visit – her first to Greece in five years – is sending a symbolic message that she wants Greece to stay in the eurozone.
Meanwhile, the International Monetary Fund said on Monday that the global economic recovery was weakening, with government policies having failed to restore confidence.
It added that the risk of further deterioration in the economic outlook was “considerable” and had increased.
Police have fired tear gas in Greece to disperse anarchists throwing petrol bombs near parliament in Athens.
Dozens were arrested during the one-day strike against planned spending cuts of 11.5 billion euros ($15 billion).
It was the first union-led action since a conservative-led coalition came to power in June.
The savings are a pre-condition to Greece receiving its next tranche of bailout funds, without which the country could face bankruptcy in weeks.
Greece needs the next 31 billion-euro installment 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.
Police have fired tear gas in Greece to disperse anarchists throwing petrol bombs near parliament in Athens
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 (ECB), and the International Monetary Fund (IMF) – to give it an extra two years to push through the austerity programme.
On Tuesday Greek 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 euros.
The Greek protest follows a series of demonstrations in Spain and Portugal, which are also facing stringent austerity measures.
An estimated 50,000 people joined Wednesday’s protests, including doctors, teachers, tax workers, ferry operators and air traffic controllers.
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.
“We can’t take it anymore – we are bleeding. We can’t raise our children like this,” Dina Kokou, a teacher, told Reuters news agency.
“We won’t submit to the troika!” and “EU, IMF out!”, “People, fight, they’re drinking your blood,” protesters chanted.
A march past parliament turned violent as anarchists wearing black balaclavas and carrying sticks threw petrol bombs and broken bits of concrete at riot police on Syntagma Square.
Images showed a policeman on fire as the bombs exploded.
The strike was called by the country’s two biggest unions, which between them represent half the workforce.
A survey conducted by the MRB polling agency last week found that more than 90% of Greeks believed the planned cuts were unfair and a burden on the poor.
Greece was given a 110 billion-euro bailout package in May 2010 and a further 130 billion euros in October 2011, backed by the IMF and the other 16 euro nations.
That money is paid in installments, but correspondents say the lenders are reluctant to stump up the latest slice, as they feel Greece has not made enough effort to meet its deficit-reduction targets.
Greece needs the new money to make repayments on its debt burden. A default could result in the country leaving the euro.