The attack by Free Syrian Army fighters occurred Friday night, The (Beirut) Daily Star reported.
"For the second time in under a week, a unit from the Free Syrian Army [consisting of] a large number of gunmen entered Lebanese territory overnight via the outskirts of Arsal, where it attacked one of the Lebanese army's posts," the Lebanese Army said in a statement.
"They attacked overnight one of the Lebanese army positions backed by a large number of armed men without causing any injuries in the ranks of the Lebanese army," the statement said.
Lebanese troops were dispatched to pursue the attackers, CNN reported.
"The leadership of the army confirms that it will not allow any party to use Lebanese territory in order to implicate Lebanon in the events of the neighboring countries," the army said.