A tear gas grenade is seen on damaged steps of a building during violent protests around Syntagma square in Athens June 29, 2011. Anti-austerity protesters attempted to block streets leading to the parliament where later today Greece's parliament holding a crucial vote on whether to submit the country to a fresh wave of unpopular austerity measures as it attempts to avoid a debt default. REUTERS/Panagiotis Tzamaros (GREECE - Tags: POLITICS BUSINESS CIVIL UNREST)