Greek workers have walked off their jobs for a 24-hour general strike that is shutting services across the country and suspending ferry routes to and from the islands.
Unions called the strike to protest against austerity measures that will continue beyond the end of Greece's third international bailout package next year.
State-run hospitals were accepting only emergency cases as medical staff joined the strike, while state schools remained shut.
Public transport was operating only for certain hours during the day, while airlines rescheduled and cancelled flights as some airport staff joined the labour action with a four-hour stoppage.
Greece has been dependent on bailouts since 2010. In return for billions of euros in emergency loans, successive governments have had to impose stringent spending cuts, tax hikes and structural reforms.