ISLAMABAD (Reuters) - Al-Qaeda has released a video marking the 10th anniversary of the September 11 attacks featuring audio remarks by new leader Egyptian Ayman al-Zawahri and previously unreleased video of slain former chief Osama bin Laden.

An hour-long video released on Monday and titled "The Dawn of Imminent Victory" was posted on jihadist websites with Zawahri shown only in a still photo, according to the SITE Monitoring Service which tracks jihadist statements.

A full translation was not immediately available.

Ahead of events in the United States to commemorate the 10th anniversary of the September 11 attacks, officials had warned of a specific, credible but unconfirmed report of a threat to harm Americans, notably in New York and Washington.

(Islamabad newsroom; Editing by Ed Lane)