A member of Lebanon's Progressive Socialist Party (PSP) died on Sunday after an attack on Saturday by supporters of the pro-Syrian Hezbollah party, the PSP reported.
The PSP, made up primarily of representatives from Lebanon's Druze population, said Lutfi Zeineddine died from injuries sustained in the attack. The attack occurred shortly after a massive rally on Saturday in downtown Beirut to commemorate the fourth anniversary of the assassination of former premier Rafik Hariri.
The PSP and Hezbollah currently work together in a national unity government. But tensions remain, as Hezbollah advocates closer ties to Syria than the PSP would prefer.
According to reports, several participants in Saturday's rally were attacked throughout Beirut. Several cars were smashed as participants drove home. At least ten people were injured in various attacks.
Hundreds of thousands attended Saturday's rally. Hariri, a five-time premier, was killed in a massive bomb blast on Feb 14, 2005. His assassination was widely blamed on Syria and its allies in Lebanon. Damascus has so far denied any involvement.
The Lebanese army, in a statement, confirmed Zeineddine's death.
"The army is tracking down several suspects in order to arrest them and hand them over to the judicial authorities," the statement said.
Hezbollah, meanwhile, denied any involvement in the clashes.
"Hezbollah was not involved in the trouble that broke out in Beirut on Saturday," Lebanese radio quoted Hezbollah sources as saying.
Shortly after the death of Zeineddine, several of his relatives blocked a major highway linking Beirut with Damascus. Angry men were seen blocking traffic and smashing cars they believed belonged to Hezbollah supporters.
Sources close to the PSP and Druze leader Walid Jumblatt told DPA that "Jumblatt is working with authorities to try to contain the situation".