Lebanese soldiers killed two gunmen during a clash with militants who were trying to infiltrate the town of Arsal from the nearby border zone with Syria, the army said on Friday.
A security source said the militants were members of the Nusra Front, al Qaeda's wing in the Syrian war.
The militants were trying to reach Arsal when the army targeted them, it said in a statement. One of the dead was identified as a Syrian. The other was unidentified.
The Nusra Front and the Islamic State jihadist group staged an incursion into Arsal last August that triggered several days of deadly battles with the Lebanese security forces.
The Lebanese group Hezbollah, which is fighting alongside President Bashar al-Assad in the Syrian war, is mounting a joint operation with the Syrian army aimed at driving both Nusra and Islamic State from the border zone.