Heavy clashes erupted on Sunday between rival factions in the northern city of Tripaolis forcing the withdrawal of the Lebanese army from the area, an army official told AFP.
The clashes in the Bab al-Tebbaneh and Jabal Mohsen areas located on the northern edge of the city began around 0645 IST pitting supporters of the country's Western-backed majority and the Hezbollah-led opposition against each other, the official said.
He said that at least 10 people were injured.
Troops could be seen deploying in other parts of Tripoli on Sunday for fear of the fighting spreading.
Similar violence had shaken the area in May.
Sunday's clashes were taking place amid stalled efforts by Prime Minister Fuad Siniora to form a new government of national unity following a breakthrough deal in May to end a long-running crisis that had brought the country to the brink of civil war.
The deal brokered in Qatar led to the election of army chief Michel Sleiman as president. The accord also calls for the formation of a cabinet in which the opposition will have veto power over key decisions and a new electoral law.