BEIRUT, Oct 18 (Reuters) - The leader of Lebanon"s Iran-backed Shi"ite group Hezbollah said on Monday that Thursday"s Beirut violence was a dangerous and important event and marked a new phase in dealing with internal politics. In his first remarks since the bloodshed that marked the worst street violence in over a decade, Sayyed Hassan Nasrallah lashed out at the Christian Lebanese Forces party and its head Samir Geagea, repeating accusations that they were responsible for the killing of the seven Shi"ites who died that day. The Lebanese Forces party, which has close ties to Saudi Arabia, has denied the accusation. Nasrallah said Hezbollah was not the enemy of Lebanese Christians. "The biggest threat for the Christian presence in Lebanon is the Lebanese Forces party and its head," Nasrallah said.