Greek hospitals and tourist sites were hit on Monday by the latest in a series of strikes by public sector workers.
Earlier police protests have resulted in clashes with fellow officers
The Acropolis and other ancient monuments were closed as policemen, firemen and coastguards and staff of the culture ministry joined large protests in Athens.
Schools and town halls were also being affected.
The strikes, over a variety of issues, were expected to continue until at least mid-week.
A nationwide strike on Thursday and Friday is expected to worsen the situation.
Other workers, including court staff, will walk out then.
Parts of the health system, including outpatient clinics, closed their doors on Monday.
The strikes have been taking place on-and-off for the past month. Unions are trying to force the socialist government's hand as it prepares its 2004 budget ahead of spring elections.
Different groups of workers involved in the wave of strikes have different complaints:
The long-running terrorism trial of 19 suspected members of the November 17 group is not being affected by the court strike.
Contract workers at tourist sites are demanding permanent staff status
The striking court employees are demanding more pay and better benefits
Police, firemen and coastguards want official recognition of the dangers of their work, entitling them to more money
Civil servants want better pay
Athens taxi drivers object to government plans to force them to issue detailed receipts to passengers.
Most of the industrial action is centred on Athens, but doctors in Piraeus are also taking part.
Some workers at historic sites at Dion, Vergina and Pella in northern Greece are also taking part, closing them to the public.
Other sites including Knossos on Crete and Mycenae and Corinth in the Peloponnese are expected to be hit later in the week.
Even the publication of Greek economic figures has been hit because statistics staff have joined the strikes.
A national strike has been called for 4 November by the Greek federation of civil servants, Adedy.