Osama bin Laden and Ayman al-Zawahiri
Osama bin Laden (L) sits with his adviser and purported successor Ayman al-Zawahiri. REUTERS

Unknown computer hackers have shut down al-Qaeda's web communications, interrupting the dreaded terrorist group's online distribution of videos and messages.

Al-Qaida's online communications have been temporarily crippled, and it does not have a single trusted distribution channel available on the Internet, Evan Kohlmann of Flashpoint Global Partners told NBC News. Flashpoint monitor's al-Qaeda's communcations.

The attack targetong al-Qaeda's web communications was carried out by some unknown hackers within the past few days, and it was well coordinated and involved the use of an unusual cocktail of relatively sophisticated techniques, Kohlmann said, adding that it will take the group several days more to fix the damage.

Al-Qaeda's web communications faced similar hacker attack last year, when the UK government broke into an al-Qaida website and replaced the instructions on how to build bombs with recipes for making cupcakes, British newspapers reported earlier this month.

The target was al-Qaeda's online magazine called Inspire, a product of al-Qaida in the Arabian Peninsula, based in Yemen. The magazine was intended for Muslims in the West.