Hackers calling themselves the "Freedom Cyber Force Militia" earlier hijacked Internet traffic destined for Al-Jazeera's Web site and redirected it to a different Web page on computers operated by Networld Connections Inc., an Internet provider in Salt Lake City. That site was shut down hours later.
The likely hacking technique, called "DNS poisoning," fools traffic-directing computers across the Internet, similar to vandalizing exit signs on an interstate to misdirect travelers. It is relatively difficult to defend against.
Internet records show the Web directories sending traffic to Al-Jazeera's site were changed early Thursday, apparently without authorization.
The page later removed also included the message, "God bless our troops," signed by a self-described "Patriot." There was no response to an e-mail sent to an address on the Web page.
"Certainly, it has been hacked," acknowledged Jihad Ali Ballout, a spokesman for Al-Jazeera. He described the attack as "a frontal, vicious attack on freedom of the press" and urged anyone with information about the hackers to contact authorities.
Hours later, the site was redirected again to another Internet provider with the message that it was "taken over by Saimoon Bhuiyan."
The Arab network's Web site has been suffering disruptions for days, ever since it showed pictures of dead and captive U.S. soldiers in Iraq.
Al-Jazeera, based in Qatar, is an unusually independent voice in the Arab world.