A commander of a group loyal to al-Qaeda was arrested by the Lebanese army on Wednesday, according to an army statement Al Arabiya reported.
The commander, Najm Abbas, is of the Abdallah Azzam brigades, the jihadist group which claimed a twin suicide attack against the Iranian embassy in Beirut last November, killing 25 people.
"After careful follow-up and monitoring, the (army) intelligence directorate in Beirut arrested the terrorist Naim Abbas, a commander of the Abdallah Azzam brigades," the army said in the statement, according to Agence France-Presse.
Shortly after the arrest, the National News Agency said soldiers were defusing a car bomb in a western neighborhood of the capital Beirut.
The Abdallah Azzam Brigades, which describes itself as loyal to al-Qaeda, has been listed by the United States as a terrorist organization since 2009.
In January, the army announced the arrest of its Saudi leader Majid al-Majid, who died days later from poor health.
Abbas' detention also follows the indictment of a Sunni Muslim sheikh, Omar Ibrahim al-Atrash, in connection with two suicide bombings in southern Beirut, a Hezbollah stronghold, that killed at least six people.
In a late January army statement on Atrash, the army had said Abbas was among three "wanted men" loyal to the Abdallah Azzam brigades and Al-Nusra Front, Syria's Al-Qaeda branch.
In recent months, Lebanon has seen a string of deadly attacks linked to Syria's war, claimed by al-Qaeda-linked groups including the Abdallah Azzam brigades.