The Lebanese army said on Saturday it had arrested a prominent Al Qaeda leader in Deir Ammar town, northeast of the city of Tripoli.
It 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 Qaeda 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 Qaeda-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.