Saturday, January 21 2006 10:28 Hrs (IST) - World Time -

Washington: CIA analysts have concluded that the voice on audio tape posted on an Islamic website is that of Al-Qaeda number two Ayman al-Zawahiri.

"Following technical analysis of the tape, CIA has assessed that it is the voice of Ayman al-Zawahiri," said the official, who asked not to be identified.

The 18-minute tape paid homage to Islamist 'martyrs' in Afghanistan but gave no indication of when it was made.

A US counter-terrorism official, who asked not to be identified, said the tape in which Zawahiri recites Arabic poetry was believed to be "something that someone pulled off the shelf and decided to post".

"There is no reason to believe it was done recently", he said.

The audio recording was posted the day after Al Jazeera television aired an audio tape of al-Qaeda leader Osama bin Laden threatening new attacks on the United States.

The messages followed reports from Pakistan that four or five top al-Qaeda figures were killed in a US air strike last week in a tribal area near Afghanistan.

An armed CIA Predator drone launched missiles at a compound where the Al-Qaeda militants, including Zawahiri, were believed to be gathering for a feast, according to Pakistani officials.

Pakistani officials subsequently concluded Zawahiri was not at the meeting but US officials have said his fate remains unknown.