Greece's most famous ancient monument, the Acropolis, became the latest stage for the country's deep political crisis on Wednesday when protesters draped it with banners calling for anti-government demonstrations across Europe.

On the twelfth day of unrest since a police officer's fatal shooting of a schoolboy triggered riots and arson, protesters unfurled two large pink banners from the stone walls of the ancient hilltop citadel, which looms over Athens.

"Thursday 18/12 demonstrations in all Europe," one banner read in Greek, English, Italian and German, while the other simply bore the word:"Resistance".