Al Qaeda releases 9/11 anniversary message

(CNN) -- A lengthy statement from al Qaeda No. 2 Ayman al-Zawahiri on the eve of the fifth anniversary of the September 11 attacks on New York and Washington calls on Muslims to step up their resistance against the United States.

Al-Zawahiri also attacks "collaborators" he says have abandoned Islam.

"The days are pregnant and giving birth to new events, with Allah's permission and guidance," Zawahiri says in a statement posted on the Internet late Sunday.

An Egyptian-born doctor from a prominent family, al-Zawahiri is al Qaeda's second in command and is thought to be bin Laden's personal physician.

More soon.