A young man injured in a Beirut clash on Sunday between supporters and opponents of Lebanese Shiite movement Hezbollah has died of his wounds, an army spokesman told AFP.
The clash broke out in front of the Iranian embassy on the outskirts of the capital, where opponents of Hezbollah were demonstrating against its involvement in fighting in neighbouring Syria.
Hezbollah supporters attacked the demonstrators, the army spokesman said.
The clash ended minutes later when the army intervened, said an AFP journalist at the scene who saw at least one person with blood streaming down his face.
Tehran is a key supporter of Syria's President Bashar al-Assad, whose regime is also backed by Hezbollah.
An army statement confirmed the protester's death.
"This afternoon, as members of a political movement arrived in the Bir Hassan neighbourhood (where the Iranian embassy is located) there was a clash during which a man opened fire with a revolver," the statement said.
"A civilian was critically injured and has since died."
Tensions in fragile Lebanon have soared since Hezbollah announced it was fighting alongside regime forces against rebels in Syria's Qusayr, which fell on Wednesday after a massive offensive lasting nearly three weeks.
In central Beirut, some 100 people also gathered to denounce Hezbollah's involvement in the Syria conflict, an AFP journalist said.
Security forces were deployed in force around the city centre to prevent any trouble.
"Hezbollah needs to get out of Syria. They are doing what no other Lebanese armed movement has ever done before, and that is to participate in a war in another country," protest organiser Charles Jabbour told AFP.
"Lebanon has never been so fragile. They are transferring the Syrian conflict into Lebanon. The Lebanese army should deploy on the border to stop Hezbollah from entering Syria," he added.
The now devastated Syrian town of Qusayr is just 10 kilometres (six miles) from the border with Lebanon.
Syria's conflict has created deep divisions among Lebanese, pitting supporters of Shiite Hezbollah against the Sunni-led March 14 movement, which supports the anti-Assad revolt.