The Lebanese army has intervened to break up clashes between rival political factions in Beirut, firing in the air to disperse crowds.
Several people were injured in the violence, which took place in three mixed Sunni and Shia neighbourhoods.
Loyalties are split in such areas between the government and the Hezbollah-led opposition.
There have been several similar outbreaks of fighting in Beirut in recent weeks.
The clashes come at a time of acute political instability in Lebanon, with pro-Syrian and pro-Western parties locked in a power struggle.
Lebanon has been without a president since November.