Osama bin Laden (L) sits with his adviser and purported successor Ayman al-Zawahri, an Egyptian linked to the al Qaeda network, during an interview with Pakistani journalist Hamid Mir (not pictured) in an image supplied by the respected Dawn newspaper November 10, 2001.[Photo/Agencies]

DUBAI - Osama bin Laden's long-time lieutenant, Ayman al-Zawahri, is now the leader of al Qaeda, Al Arabiya television reported on Thursday.

The Egyptian-born Zawahri vowed earlier this month to press ahead with al Qaeda's campaign against the United States and its allies, in what appeared to be his first public response to bin Laden's death in a US commando raid in Pakistan in May.

The news channel gave no further details.

Zawahri, whose whereabouts are unknown, had been seen as bin Laden's most likely successor.