Riot policemen assist a colleague whose clothing caught fire after being hit by a petrol bomb during rioting in central Athens, Oct. 20, 2011.

A man shouts while helping an injured demonstrator during clashes between communists and black-clad youths near the Parliament building in Syntagma (Constitution) square in Athens October 20, 2011. Angry protesters vowed to bring Greece to a standstill on Thursday while disgruntled lawmakers vote on the details of a deeply unpopular austerity package needed to stave off bankruptcy.

A protester sits bleeding during clashes between communists and black-clad youths near the Parliament building in Syntagma (Constitution) square in Athens October 20, 2011.

Communists, left, clash with black-clad youths near the Parliament building in Syntagma (Constitution) square in Athens October 20, 2011.