Lebanese security officials say at least six people have been wounded in clashes in southern Beirut, amid rising tensions following the assassination of a top security official.
Soldiers and tanks were deployed between Sunni and Shi'ite neighborhoods in the capital's Kaskas district Monday, trying to bring calm to the area.
Separate fighting in the northern Lebanese city of Tripoli killed at least one person and wounded 10 others.
Meanwhile, a group of protesters has set up tents outside Lebanese Prime Minister Najib Mikati's office, vowing to remain there until he resigns.
The sit-in began late Sunday outside the building in central Beirut. Earlier Sunday, Lebanese security forces fired their weapons into the air and used tear gas to disperse protesters who were trying to storm the building.
The demonstrators are demanding Mr. Mikati quit over the assassination of Brig. Gen. Wissam al-Hassan, a top intelligence official who died along with seven others in a car bombing Friday that many blame on the government in neighboring Syria.
Former Lebanese prime minister Saad Hariri and opposition leader Walid Jumblatt have both accused Syrian President Bashar al-Assad of being behind the blast. Prime Minister Mikati's government is supported by Lebanon's pro-Syrian Hezbollah militia.