Flights in Greece were at a standstill on Thursday after air traffic controllers called a 24-hour strike over pension reforms sought by the country's creditors.
The strike, due to end at 2059 GMT, halted all flights into and out of the country, Athens airport said.
"Nothing is moving today," its press office said.
The strike is also being followed in government offices, schools and hospitals, in a protest organised by the civil service union Adedy.
Unionised Greek journalists also stopped work, affecting news channels and new websites.
Several hundred people on Thursday set out on a 220-kilometre (136-mile) "right-to-work" march from Patras, Greece's third biggest city, to Athens.
Greece's creditors are calling for an overhaul to pensions and tax in exchange for the lifeline they threw to the debt-crippled country last July.
The government of Alexis Tsipras plans to lower the maximum pension to 2,300 euros ($2,500) from 2,700 euros, and introduce a new minimum guaranteed basic pension of 384 euros.
The government resumed talks on Monday with the European Union, the European Stability Mechanism, the European Central Bank and International Monetary Fund on the next phase of of savings due under the bailout, worth 86 billion euros ($98 billion).