The official National News Agency said demonstrators took to the streets of Sidon following Friday prayers.
"Protesters tried to cut off the west lane of the highway through the city, but the army prevented that, pushing them to disperse," the news agency stated.
Lebanese forces in June captured a compound in the coastal city of Sidon held by Assir, a cleric critical of Syrian President Bashar Assad and his Shiite supporters, Hezbollah. At least 17 members of the Lebanese military were killed in the melee.
Hezbollah strongholds in southern Beirut have come under attack since the Shiite movement admitted to fighting in Syria alongside pro-government forces this year.
The New York Times reported Friday the Israeli military conducted an airstrike on a Lebanese target after four rockets were fired from across the border earlier this week.
Hezbollah Secretary-General Hassan Nasrallah took responsibility for an explosion last week that injured four Israeli troops.
The BBC reported at least 27 people were killed and more than 350 were injured in twin blast in the northern city of Tripoli after Friday prayers ended at a Sunni mosque.