Syrian troops fired rocket propelled grenades into northern Lebanon during the night, sparking panic among the local population, a security official and residents said on Thursday.
The security official said heavy machinegun fire erupted at around 9:00 pm (1900 GMT) from the Syrian side of the border, near the Lebanese village of Muqaybleh, prompting some residents to flee.
There were no reports of casualties.
"The Syrian troops initially fired flares and then machineguns and rocket propelled grenades," the official, who requested anonymity, told AFP.
He said at least two rockets fell inside Lebanese territory.
Lebanese media also reported shelling near the region of Al-Qaa, located in the eastern Bekaa.
Thousands of Syrians have fled to Lebanon since a revolt against the regime of Syrian president Bashar al-Assad broke out in March last year.