Greek police clashed with demonstrators, who threw rocks, bottles, flares and gasoline bombs outside the Israeli Embassy in Athens on Tuesday during a protest against the two-week bombardment of Lebanon. Police fired tear gas at the protesting youths, who quickly dispersed. There were no immediate reports of injuries or arrests. The troubled started after 2,000 demonstrators, chanting "Israel Killers," marched to the embassy. The rally _ the fourth in Athens since Israel launched attacks - was backed by Greece's largest trade unions and local anti-globalization groups.