Websites shut down
The US said that any video message would be closely scrutinised and that efforts to capture the al-Qaeda continued.
Soon after Washington announced it had the video, all the websites that usually carry statements from al-Qaeda went down and were unaccessible, in an unprecedented shutdown, according to the Associated Press news agency.
The reason for the shutdown was not immediately known.
"The US said that any video message would be closely scrutinised and that efforts to capture the al-Qaeda continued"
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Evan H Kohlmann, an expert at globalterroralert.com, said he suspected it was the work of al-Qaeda itself, trying to find how the video leaked to US officials.
Others suspected US hand behind the shutdown.
Bin Laden was last seen in a video statement shortly before the US presidential election in 2004.
Since then, he has issued a number of audio messages, the last in July 2006 when he vowed al-Qaeda would fight the US across the world.
Bin Laden is believed to have escaped US efforts to capture him during a December 2001 battle in Afghanistan's Tora Bora mountains.
He is now thought to be hiding in the remote tribal areas along the Pakistan-Afghanistan border.
Last year, a leaked French intelligence report said Saudi secret services thought bin Laden had died of typhoid in Pakistan, but Saudi Arabia said such reports were just speculation.
The website that carried the notice showed a still photograph purportedly from the coming video, with bin Laden addressing the camera, his beard fully black.
In his past videos, bin Laden's beard was almost entirely grey with dark streaks.
Bin Laden's beard appears to have been dyed, a popular practice among Arab leaders, Rita Katz, director of the SITE Institute, a Washington-based group that monitors "terrorist" websites, said.
"I think it works for their [al-Qaida's] benefit that he looks young, he looks healthy," she said.