Lebanese security officials said five shells hit a border town six miles inside Lebanese territory Wednesday morning, The Daily Star newspaper reported. There was no word on casualties or claims of responsibility.
Syrian forces struck alleged rebel targets along the Lebanese border Monday. Damascus sent a letter to Lebanese defense officials last week warning that it may take military action against armed gangs suspected of crossing the Lebanese-Syrian border.
Syria's war has threatened to spill into neighboring Lebanon.
Lebanese Parliament Speaker Nabih Berri said in early March that he was concerned about stability in his country given regional strife. Nabih's March 8 coalition includes members of Hezbollah; he added there are growing signs of an al-Qaida presence in Lebanon.
Syria's civil war entered its second year this week. The United Nations estimates at least 70,000 have died and more than 1 million people have been displaced by the conflict.
The European Union estimates that, since of the end of February, more than 325,000 Syrian nationals have fled to Lebanon.
U.S. Navy Adm. James Stavridis, NATO's supreme allied commander for Europe, told the Senate Armed Services Committee this week that "we are prepared if called upon to be engaged" in Syria.