named him its new leader in June following the death of Osama bin Laden in a U.S. commando raid in Pakistan.
The Egyptian-born al-Zawahri, who long served as bin Laden's top deputy, directly addressed the Syrian protesters who have risen up against Assad's rule despite a bloody government crackdown. The message appeared to be an attempt to place al-Qaeda firmly on the side of the anti-government demonstrators.
"You are an example, explaining lessons to your Arab and Muslim nation in sacrifice, steadfastness and the struggle against oppression," al-Zawahri said of the protesters. "How could you not? You are the sons of the Levant, the front for jihad and martyrdom."
In the past, al-Qaeda leaders, including bin Laden himself in a video released after his death, have sought to associate themselves with the uprisings sweeping the Arab world this year, offering guidance on how the protests should be led to serve al-Qaeda's extremist version of Islam.
Many experts, however, think the uprisings have shown how out of touch the terror group has become with the aspirations of Arab youth who have been the uprising's main activists. Most seek greater freedom from dictatorial regimes, not the Islamic rule al-Qaeda advocates.
And in Syria, activists have said religion has played little role in their uprising to topple Assad.
In the video, Zawahri — dressed in a white robe, large glasses and a turban, with an assault rifle at his side — also warned the Syrian protesters not to believe that President Barack Obama and the United States stand with them.
"Tell America and Obama: … we are waging a battle of freedom and liberation, freedom from corrupt tyrants and the liberation of the religion of the Muslims," al-Zawahri said.
Al-Zawahri claimed that Washington wants to replace Assad with "a new ruler who follows America, protects Israel's interests and grants the (Muslim) nation a few freedoms."
The U.S. administration has toughened its rhetoric toward Assad's regime, declaring recently that the Syrian leader has lost all legitimacy as a leader.
Al-Zawahri also attacked Assad, calling him "the leader of the criminal gang, descendant of the traitors, biggest of those who spread corruption, head of the executioners, America's partner in the war on Islam in the name of terrorism, and border guard for Israel."