The largest "Indignados"-style gathering -- named after the initiatives that first sprung up in Spain's main plazas -- took place in Athens' central Syntagma Square on a balmy Sunday afternoon and evening.

The social media-fuelled sit-down protest covered most of the square by late afternoon in front of Greece's Parliament, while a handful of other main plazas across cities in Greece hosted the same type of protests.

The mobilisations in Greece coincided with similar rallies across European cities.

As of 10 p.m. local time (20.00 GMT), the sit-down protest continued in an entirely peaceful manner, mostly with chants against political parties and politicians. Streets adjacent to Syntagma Square were blocked off.