Thousands of people flooded central Athens Sunday evening on the fifth day of protests against government austerity policies after an online campaign inspired by Spanish demonstrators.

About 50,000 people assembled in the Greek capital's central Syntagma Square, police estimated, responding to calls on social networking sites for gatherings across Europe to demand "real democracy".

Sunday's gathering appeared to be the largest since protests began on Wednesday after the plans were circulated on Facebook.

The non-political, non-ideological demonstrations are modelled on a similar mobilisation in Spain led by a group calling themselves "the indignants."

In greater numbers than on any night since the protests began earlier this week, the 'Indigants' kept the date made via Facebook and other social networking sites on Sunday, descending upon Syntagma Square for yet another sit-down demonstration against severe austerity cuts. This night they were joined by others in Milan's Piazza del Duomo, Bastille in Paris and another 100 cities of Europe that held a simultaneous peaceful protest.

People started arriving promptly at 6:00 p.m. and an hour later it was clear that Sunday's demonstration would be the largest of five consecutive protests that have taken place each night at Syntagma opposite Parliament since Wednesday.

With their numbers in the tens of thousands, people have filled Syntagma and spilled out onto nearby Voukourestiou, Panepistimiou and Stadiou and Filellinon streets. Metro trains are no longer stopping at Syntagma, reaching only as far as Evangelismos, and access to the city centre is impossible.

So far the demonstration has been entirely peaceful, without violent incidents as chants against parties and politicians alternate with booing, banging of pots, drum music and whistles.

The demonstrations have drawn a kaleidoscope of people of all age groups and walks of life that have gathered to protest against unemployment, tax hikes and more cuts. Those in the square made a mismatched crowd, with school children and youths in rasta braids rubbing shoulders with chic 40-somethings in suits and old-age pensioners. Most of the people arriving had nothing more in common than facebook friends and shared anger at the politicians they hold responsible for the state of the country's economy.

The groups that came every day had started to organise, setting up committees to take charge of hygiene, food, legal support and medical care and there were more tents than in all previous days. Today, for the first time, there was also a stronger police presence than on previous days.

As on other days, the Syntagma demonstration was matched by similar gatherings in other Greek towns, most notably the northern Greek city of Thessaloniki, where heavy rain at around 6:00 p.m. proved unable to deter protestors.