CAIRO: In a message Tuesday marking the Sept. 11 anniversary, al Qaeda's new leader sought to claim credit for this year's Arab uprisings, saying the 2001 attacks on the United States paved the way for the ''Arab volcano'' sweeping the region a decade later.

Ayman al-Zawahri and other al Qaeda figures have issued a number of messages seeking to associate themselves with the Arab uprisings that toppled autocratic leaders in his native Egypt, as well as Tunisia and Libya, and which threaten others. In the messages, they urge Arabs to replace toppled regimes with Islamic rule.

The wave of unrest transforming the Middle East, however, was largely the work of young, peaceful protesters seeking democratic freedoms, and political observers say it showed the failure of al Qaeda's extremist ideology and how out of touch the terror group is with Arab youth.

''By striking the head of the world criminal,'' al Qaeda forced America to press its allies in the Middle East to change their policies, which helped the ''Arab volcano'' to build up and explode, al-Zawahri said in the hour-long audio message.

Al-Zawahri was Osama bin Laden's deputy and became head of al Qaeda in June after bin Laden's death in the May 2 raid by US Navy SEALs in Pakistan. Al-Zawahri had a long history of fighting against Hosni Mubarak's rule in his home nation, leading militants who carried out deadly bombing and shooting attacks in the 1990s.

Islamic militants considered the regimes of Mubarak and other US-allied autocrats in the Middle East to be corrupt, godless and too closely aligned with the West.

Their attacks were met with a crackdown by Mubarak's security forces that largely crushed their operations in Egypt.

In his new message, titled ''The Dawn of Imminent Victory,'' al-Zawahri also lashed out at the United States for what he called ''blatant deception'' in showing support for the Arab uprisings while keeping strong ties with leaders in the absolute monarchies of the Gulf, like Saudi Arabia.

''Why doesn't it (the US) say anything to Al Saud, the killers of Muslims and the thieves of their wealth,'' he said, referring to the Saudi ruling family.

The new message released by al Qaeda's media arm and posted on extremist websites included previously unreleased footage of bin Laden.

The US was on high alert during the weekend over what officials described as a credible but unconfirmed terror threat on Washington or New York.