Security sources told Lebanese newspaper The Daily Star on condition of anonymity that three people were injured in a gun battle in southern Beirut after arguments erupted over men hanging a banner to honor the Shiite holy day of Ashura, which falls on Nov. 24.
The report adds that two others were wounded in separate clashes overnight.
Lebanon is on edge following the October assassination of a top intelligence chief. Opposition leaders suspect the Syrian government may have played a role in the attack.
Lebanon, before the 2005 revolution, was influenced heavily by the Syrian government. With civil war raging across the border, world leaders have expressed concern about the stability in Lebanon.
The U.S. State Department, in a readout of the meeting, said Burns "emphasized the United States' commitment to a stable, sovereign, and independent Lebanon."