Beirut: Lebanese military authorities have arrested the leader of the Abdullah Azzam Brigades, the offshoot of al-Qaeda that claimed responsibility for the double suicide bomb attack on the Iranian Embassy in Beirut in November, according to Lebanese news media.

The leader, Majid al-Majid, is a Saudi national whose radical Sunni group is closely allied with al-Qaeda in Iraq. The reports did not say when the arrest took place.

The Abdullah Azzam Brigades came into being years before the conflict across the border in Syria, but the group has allied itself with extremists among the rebels fighting President Bashar Assad there and threatened more attacks if the Lebanese Shiite militia Hezbollah did not stop sending its fighters to support him. Recently, Al-Majid reportedly pledged allegiance to the Nusra Front, another al-Qaeda-linked group fighting in Syria.

Iran and its Lebanese ally, Hezbollah, which is also Lebanon's most powerful political party, have backed Dr Assad, while their Sunni Lebanese rivals have supported the insurgency. Hezbollah has sent fighters to aid the government, and Lebanese Sunni militants have joined the rebels.

The war in Syria has been a fruitful recruiting tool and training ground for extremist Sunni militants in Lebanon, who have a longstanding presence but had been seen as fairly marginal before the Syrian conflict. Until now, they have been mainly confined to pockets in Palestinian refugee camps outside the control of Lebanese authorities. Al-Majid is said to have lived in one until recently.