Lebanese security sources say gunfire has erupted at a demonstration in Beirut, killing a man who was protesting against the involvement of Shi'ite militant group Hezbollah in the Syrian civil war.
It was not clear who killed the man at Sunday's small protest outside the Beirut embassy of Iran, which is a supporter of Hezbollah and Syrian President Bashar al-Assad, whose Alawite sect is an offshoot of Shia Islam.
Anti-Hezbollah activists held a second small protest in another part of the Lebanese capital. It ended without reports of violence.
Hezbollah recently acknowledged sending forces across the border into Syria to fight on behalf of President Assad against predominantly Sunni rebels waging a two-year battle to oust him.
The group's involvement in the Syrian conflict has raised sectarian tensions in Lebanon, whose fractious religious communities include Shi'ites and Alawites largely supportive of Assad and Sunnis who mainly back Syria's rebels.
Armed Lebanese supporters and opponents of Mr. Assad have fought several deadly battles in the northern city of Tripoli in recent months. The violence has raised international concerns about the spillover of the Syrian civil war into neighboring countries.