A general strike against tough austerity measures is under way in Greece, with trade unions calling for "mass mobilization" of protesters, BBC News reported.

The 24-hour action is expected to severely disrupt public services, including transport and hospitals. The organizers are demanding an end to spending cuts and tax rises.

The government says the measures are badly needed to lead Greece out of a deep financial crisis and six straight years of recession.

The cabinet of Prime Minister Antonis Samaras says the policies are part of continuing moves to ensure more bailout money from international creditors.

The 24-hour strike officially began at midnight. Trains and ferries are at a standstill, other public transport is disrupted and hospitals are working with reduced staff.

In Athens, hundreds of people rallied outside parliament in Syntagma Square, waving flags and banners. Demonstrations are planned across the country, with police on alert for a repeat of past violence.

The two largest unions - GSEE and ADEDY - have said that the action will focus on demands to end austerity.

They say that government measures have led to the country's record unemployment rate of 27%, including almost 60% among young people.