DUBAI - TWO of the main Internet sites used by Al-Qaeda and its affiliated groups have been blocked for the past six weeks, one totally unoperational the other pointing readers to the joker.com website.

The sites, which had been used by Al-Qaeda to spread jihadist propaganda messages, have not been accessible since this year's seventh anniversary of the September 11 attacks on the United States.

Al-Ekhlaas.net, which long served as an online message board for Al-Qaeda leader Osama bin Laden and his deputy Ayman al-Zawahiri as well as for jihadists in Iraq, Afghanistan and Somalia, now merely boasts a message by 'Your Joker.com Team'. 'The Domain was Successfully Registered with Joker.com,' the message reads.

'To administer the domain, configure your email addresses and URL forwarding, or register more domains, please go to Joker.com.' Alhesbah.net, a second site used by Bin Laden's network, is totally inaccessible.

The closure of the two sites has significantly reduced the capacity of Al-Qaeda to distribute its messages, which were popular in jihadist forums and were often commented on by Internet surfers.

Until now, Al-Qaeda has managed to overcome all attempts to block its sites.

It was not clear who was responsible for the blocking, but there were hints that it might have been Shiite Muslims acting against the Wahabi sect of Sunni Islam represented by Al-Qaeda.

The jihadists' sites are not the only ones to have been invaded in what appear to be tit-for-tat attacks by rival cyber experts from the Sunni and Shiite strands of Islam.

On October 10, Dubai-based Al-Arabiya television announced that its Internet site had been attacked by 'extremist' hackers.

'If the attacks against Shiite Internet sites continue, none of your Internet sites will be secure any longer,' flashed a short message in Arabic and English on its homepage before the site was restored.

In September, dozens of Shiite Internet sites, belonging in particular to religious dignitaries in Iran's holy city of Qom, were attacked by Wahabi hackers, according to Iran's semi-official Fars news agency.

'The hacker group 'XP', related to the Wahabis, attacked 300 Shiite sites, in particular the site 'Al-Beit', the greatest Shiite site in the world,' it said, referring to the foundation of the same name established by Iraqi Shiite cleric Grand Ayatollah Ali al-Sistani.

Western law enforcers have long been worried about the proliferation of Islamist websites that, via propaganda and training manuals, give would-be militants the inspiration and know-how to execute terror attacks. -- AFP