IntelCenter said the video or audio message, entitled "Come to Jihad," was expected to be released in the next 72 hours.

Meanwhile, in another video released by Al-Qaeda's media arm, Al-Sahab, bin Laden's deputy Ayman al-Zawahiri also warned that Musharraf would be "punished" over the killing of a Pakistani cleric killed in the storming of the Red Mosque in Islamabad in July.

In the new video aired on Thursday to mark the sixth anniversary of the Sept 11 attacks, Zawahri called on Muslims to fight the United States and its allies around the world.

"Stand oh nation of Islam under the victorious banner of the Prophet ... and campaign against the Crusader banner of (US President George W.) Bush," Zawahri said in the tape.

"Go forth ... to the mujahideen, bear them arms, back them, defend them and don't be intimidated by the power of America for these two blessed attacks have revealed that it is a power of iron and fire, with no faith or morals or principle."

Zawahri, who praised the actions of al-Qaeda-linked groups fighting in Afghanistan, north Africa, Somalia, Chechnya and Iraq, called on Pakistanis to avenge the killing of a rebel cleric sympathetic to Afghanistan's Taliban in July.

"Let the Pakistani army know that the killing of Abdul Rashid Ghazi and his students and the demolition of his mosque and two madrasas have soaked the history of the Pakistani army in shame, which can only be washed away by retaliation against the killers of Abdul Rashid Ghazi and his students."

At least 75 of Ghazi's followers were killed in an assault on the Lal Masjid, a mosque and school complex. The group is sympathetic to the Taliban, who were removed from power in Afghanistan by US-led forces.

The video was the third featuring high-profile Qaeda leaders to be issued by al-Qaeda's media arm, As-Sahab, this month to mark the Sept. 11, 2001, attacks on New York and Washington in which almost 3,000 people were killed.

Al-Qaeda leader Osama bin Laden appeared in a new video on Sept. 7 in which he said the United States was vulnerable despite its economic and military power and said only conversion to Islam would end the conflict.

In an audio tape issued on Sept. 11, bin Laden praised what he called the "19 champions" who carried out the attacks and eulogised one hijacker, who presented his last testament.

The latest tape is an 80-minute compilation including old audio clips from bin Laden, comments by Qaeda fighters and clips of Western analysts and officials. Zawahri gives what appears to be a new commentary, explaining how the United States was being defeated by Muslims around the world.

"What they claim is the strongest power in the history of mankind is today being defeated in front of the Muslim vanguard of jihad six years after New York and Washington," said Zawahri, who was speaking in front of a packed book case. An assault rifle leant against it.

"The coalition of the Crusaders has begun to fight the fight of the desperate by increasing its bombing of civilians to discourage them from supporting the Taliban."

The video does not appear to contain any new material from bin Laden. It begins with footage of a cockpit and what analysts said was old audio tape of Mohammed Atta, a leader of the September 11 hijackers, talking to passengers aboard the doomed plane.