A Syrian flag and statement denouncing Al Jazeera's "positions against the Syrian people and government" were posted on the Arabic site of the channel in response to its coverage of the uprising against President Bashar al-Assad which began in March last year.

Al Jazeera took the lead in covering the uprisings across the Arab world, and Qatar, one of the Sunni-led states in the region, publicly backed the predominantly Sunni rebel movement in Syria against Assad's Alawite-led government.

Opposition activists on Twitter blamed the hacking on Assad loyalists.

Jazeera officials were not immediately available for comment.

The hacking attack, claimed by a group calling itself "al-Rashedon", is the latest in a wave of cyber attacks on news agencies and energy companies, carried out by hostile governments, militant groups or private "hacktivists" to make political points.

Last month, Qatar's Rasgas, the world's second-biggest liquefied natural gas (LNG) exporter, found a virus in its office computer network, just two weeks after the world's biggest oil producer, Saudi Aramco, in neighbouring Saudi Arabia was hacked into.

The blogging platform of the Reuters News website was also hacked last month and a false posting saying Saudi Arabian Foreign Minister Prince Saud al-Faisal had died was illegally posted on a Reuters journalist's blog.

Although the identity of those hackers is not known, there is an intensifying conflict in cyberspace between supporters and opponents of Assad. Saudi Arabia has emerged as a staunch opponent of Assad.

(Reporting by Rania El Gamal in Dubai and Erika Soloman in Beirut, editing by Tim Pearce)

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