Al-Qaeda\'s new leader Ayman al-Zawahiri praised anti-regime protestors in Syria in a video released Wednesday claiming the United States is seeking regime change in Damascus, US-based monitors said. Calling the pro-democracy activists \"mujahideen,\" or holy warriors, Zawahiri hailed their efforts in \"teaching lessons to the aggressor, the oppressor, the traitor, the disloyal, and standing up against his oppression\" in a video the SITE Intelligence Group said was posted on extremist online forums. He also expressed regret that he and his fellow fighters could not join ordinary Syrians in their uprising against the regime of Syrian President Bashar al-Assad, which has responded with a brutal crackdown that has left at least 1,486 civilians dead since mid-March, according to rights groups. Instead, Zawahiri said the ongoing war between the United States and its allies against Al-Qaeda, along with the \"barriers and borders\" between Arab and Muslim countries was preventing him from joining the struggle in Syria. \"If it were not for that -- my brothers and I would have been amongst you and with you, defending you with our lives,\" Zawahiri said in the video which appeared to be dated from June. Zawahiri, wearing a white garb and turban, claimed the US was seeking to overturn the Syrian government and replace it \"with another regime that squanders your revolution and jihad in a new regime that follows America, takes care of Israel\'s interests and grants the Ummah (nation) some freedoms.\" Long Al-Qaeda\'s number two, Zawahiri took over the helm of the group after Osama bin Laden was killed in May during a US special forces night raid deep in Pakistan. His latest video clocked in at seven minutes, five seconds. Some rights groups say at least 12,000 people have been detained in Syria since the anti-regime protests erupted, but it is unclear how many are still being held and how many have been released.