BEIRUT (REUTERS) - Lebanon confirmed on Friday that a man in army detention is the alleged leader of an Al Qaeda-linked militant group that operates throughout the Middle East.

US national security sources on Tuesday had confirmed the detention of Majid bin Muhammad al-Majid, reported leader of the Abdullah Azzam Brigades, but Lebanon had refrained from commenting on his identity before DNA results were known.

"After conducting a DNA test, it is clear that he is the wanted Saudi national Majid al-Majid," a report published on the army's website said on Friday.

The group has claimed attacks across the region, most recently a double suicide attack on the Iranian embassy in Beirut in November, which killed at least 23 people.

In tweets at the time of the bombing, it threatened more attacks in Lebanon unless Iran pulls its forces out of Syria. An increasingly sectarian civil war there has attracted Sunni and Shi'ite fighters from neighbouring countries as well as military support and economic aid from Iran.

Last year, the Azzam Brigades, named after an associate of the late Osama bin Laden, were formally designated by the US State Department as a foreign terrorist organisation.

The State Department said the group was divided into two branches: one called the Yusuf al-'Uyayri Battalions, named after a founder of Yemen-based Al Qaeda in the Arabian Peninsula, and the Lebanon based Ziyad al-Jarrah Battalions, named after one of the airliner hijackers who attacked New York and Washington on Sept 11, 2001.