Ferry and train services in Greece have ground to a halt as unions hold a strike for May Day.

Hundreds of people are gathering for planned rallies in central Athens to mark the day.

The country's main unions are protesting over soaring unemployment, which is the highest in the 27-country European Union, and the austerity measures the government is enacting in return for crucial bailout loans.

Greece nearly went bankrupt in 2010 and has since depended on money from its eurozone partners and the International Monetary Fund, granted on condition the government pursues deep spending cuts and wide-ranging economic reforms.

While the austerity has succeeded in reducing high budget deficits, it has been at a huge cost, with the country in its sixth year of deep recession.