Lebanese security sources told The Daily Star newspaper on condition of anonymity that members of the Free Syrian Army were attacked on their way to a hospital this week. Clashes erupted in northern Lebanon following kidnappings in the region, the newspaper reports. It wasn't clear if the incidents were related.
At least 12 people were killed in three days of fighting between pro- and anti-Syrian groups in Tripoli.
Lebanon has been on edge for most of the year as the civil war in Syria threatens to spill across the border. March marked eight years since Lebanon broke free of Syrian influence during its Cedar Revolution.
The British government last week expressed concern about Lebanon's internal stability following the resignation of Prime Minister Najib Mikati. British Foreign Minister William Hague said Mikati's resignation and violence in Tripoli added to the list of growing Lebanese concerns.
The U.S. State Department confirmed U.S. Secretary of State John Kerry spoke with Lebanese officials but stressed Lebanon's politics were internal matters.
Mikati hails from the March 8 coalition, a political slate that includes members of Hezbollah.
Notable deaths of 2014 [PHOTOS]