The first general strike in Greece in a year takes place as public and private sector workers are set to walk off from their jobs on Thursday to protest austerity measures demanded by the international creditors.
Many services - including public transportation, schools and pharmacies are closed - while hospitals remain open only for emergencies. All of the museums and archeological sites are closed.
Street protests started at 08:30 GMT in Athens.
"We are fighting against government measures that perpetuate medieval labour relations ... we react to any austerity measure that downgrades our lives," said leading union GSEE (General Confederation of Greek Workers).
The governing leftist SYRIZA party announced support for the unions holding the strike as Prime Minister Alexis Tsipras faces the first general strike since he assumed power on an anti-austerity platform.
Despite promising to end the austerity program imposed by the country's creditors, Tsipras had to sign a new 3-year 86-billion euro ($93 billion) bailout plan with steep tax hikes and spending cuts.
Following a revolt in the ranks of SYRIZA, Tsipras called for early elections in September and formed a second government afterwards, promising to implement the bailout measures yet vowing to work to mitigate the conditions.
"Amid negotiations, the demands of workers and labour action are of significant importance and this must be used against the neo-liberal policies and blackmail," SYRIZA said referring to the negotiations between the Greek government and its creditors for the release of bailout funds.
On the other hand, the European Commission, the European Central Bank, the International Monetary Fund and European Financial Stability Facility (EFSF) held a meeting for Greece with the purpose of making a pledge for the country's third bailout program.
Eurozone finance ministers on Monday said that Greece has so far not made the reforms necessary for the release of a 2 billion euro ($2.2 billion) disbursement.
The Eurozone ministers said Greece has one week to deliver on its promises as Tsipras on Tuesday told his cabinet to finalise the talks within the week.
The current talks will also decide whether a 10 billion euro ($10.1 billion) fund is released for the recapitalisation of four major Greek banks.
The European Central Bank in October said that Greek banks need 14.4 billion euros ($15.8 billion) to stay afloat in case of any shocks.
On late Wednesday Greek Economy Minister George Tsathakis said that a deal could be reached by the weekend. "I believe we will have closed all the issues by Saturday," he said.
Protesters were confused that leftists are protesting a leftist SYRIZA party. This paradox was reflected in social media, as one user said: "I'm confused. Are we marching with Alexis to topple Tsipras, or with Tsipras to topple Alexis?"