The Lebanese army said on Saturday it had arrested a prominent al-Qaida leader in Deir Ammar town, northeast of the city of Tripoli.
The army identified the arrested man only as "T.M." and said in a statement that the arrest took place on Friday.
"T.M. is one of the most prominent leaders of al-Qaida and the founder of its cells in Lebanon," it added.
"He has also played a key role in establishing the terrorist Fatah al-Islam organization," the statement added, referring to an al-Qaida-inspired militant group that used to be active in Lebanon over a decade ago.
The Lebanese army said T.M. withdrew from the spotlight in late 2007 following a fierce battle between the military and Fatah al-Islam at a refugee camp in northern Lebanon.
He then returned to prominence after the rise of the Islamic State and Syrian militant group the Nusra Front, the army added.