Protesters stand amongst tear gas as a petrol bomb explodes during clashes in Athens. (October 20, 2011)

Rioters and police scuffle as an officer tries to arrest a man during clashes in Athens' main Syntagma square. (June 15, 2011)

A motorcycle policeman tries to remove his helmet as he burns after protesters throw a petrol bomb in Athens. (February 23, 2011)

A riot policeman strikes a demonstrator as protesters try to prevent deputies from reaching the Greek parliament in central Athens. (June 29, 2011)

A nurse shouts slogans during a protest by hospitals staff in Athens. (October 13, 2011)

A nurse shouts slogans during a protest by hospitals staff in Athens. (October 13, 2011)

Pedestrians pass a plaque of a Greek one-drachma coin, which was replaced by the euro in 2002, outside Athens City Hall. (November 2, 2011)

A protester clashes with riot police outside the Greek parliament in Athens. (February 12, 2012)

Protesters gesture as they hold a banner with an E.U. flag and swastika in the center during a peaceful rally for a sixth day, attended by thousands called through a social networking site - modeled on protests by young people in Spain. (May 30, 2011)

Demonstrators confront riot police at Syntagma square in front of the Greek Parliament in central Athens, during a rally against plans for new austerity measures. (June 15, 2011)

A man uses his cell phone in front of chart with the stock prices at the Greek Stock Exchange in Athens. (October 4, 2011)

A protester throws a stone at police at Syntagma square in front of the Greek Parliament in central Athens. (June 29, 2011)

Riot policemen are covered by red paint thrown by protesters during clashes in Athens. (October 19, 2011)

A protester uses a metal pole against riot police during clashes outside the Greek parliament in Athens. (October 19, 2011)

Protesters lie on the ground, pretending to suffocate, in front of the Greek Parliament during a protest organized through a social-networking site. (June 1, 2011)

A protester kicks motorcycle police during clashes in Athens. (October 19, 2011)

Protesters attacks a riot police fence during clashes outside the Greek parliament in Athens. (October 19, 2011)

Riot policemen's clothing catches fire after protesters threw petrol bombs during clashes in Athens. (Oct. 20, 2011)

Protesters dressed as prisoners gather during an event to protest against austerity measures outside the Greek parliament in Athens. (November 1, 2011)

A pedestrian walks past an entrance to a building damaged during clashes in Athens.(October 19, 2011)

Greek Prime Minister George Papandreou returns to an emergency cabinet meeting after he took a short break at the Greek parliament in Athens. (November 3, 2011)