Ayman al-Zawahri, global head of al-Qaeda since the death of Osama bin Laden last May, issued the call to arms in an eight-minute video posted on an Islamic website on Sunday entitled "Onwards, Lions of Syria".
Dressed entirely in white, with an assault rifle displayed by his side, Egyptian born al-Zawahri urged Muslim states including Iraq, Lebanon and Jordan to come to the aid of Syrian protesters and urged Syrian protesters not to ally themselves with the Western powers, including the US and the United Nations, or the Arab League.
"Our people in Syria, don't rely on the West or the United States or Arab governments and Turkey," Mr Zawahri said."You know better what they are planning against you. Our people in Syria don't depend on the Arab League and its corrupt governments supporting it."
The Arab League is expected to meet next week to discuss forming a joint UN-Arab mission to send to Syria following the recent failure of a team of UN monitors to quell the civil violence, now entering its eleventh month.
In Homs, activists say hundreds have been killed in a week of intense, renewed shelling by government forces.
"Wounded Syria still bleeds day after day, while the butcher, son of the butcher Bashar bin Hafiz (Hafez al-Assad), is not deterred to stop.
"But the resistance of our people in Syria despite all the pain, sacrifice and bloodshed escalates and grows," Mr Zawahri said, in his second video message to the Syrian people.
In June, the terrorist leader dismissed US support for Syria's pro-democracy activists as insincere and asked protesters to extend their opposition to Washington and Israel.
US officials claim the Iraqi branch of al-Qaeda is responsible for two recent explosions in the Syrian capital Damascus and was almost certainly behind last Friday's suicide blast in Aleppo, which killed 28 people. US intelligence reports suggest the bombings were carried out on the orders of Mr Zawahri, who they suspect is attempting to hijack the violent events in Syria and reassert al-Qaeda's presence in the region.
