Al-Qaeda leader Ayman al-Zawahiri said that Lebanese Shiite militant group Hezbollah had been exposed as a tool of Iranian expansionism, in an audio message posted online on Wednesday.
Zawahiri said that Hezbollah leader Hassan Nasrallah's public acknowledgement in late April that its fighters had intervened in neighbouring Syria in support of President Bashar al-Assad, a key Tehran ally, "tore off the mask he always hid behind."
"The jihadist uprising in Muslim Syria has exposed the ugly face of Hasan Nasrallah, the head of the rejectionist (Shiite) Safavid (Iranian) plan for Syria," the Al-Qaeda leader said.
Sunni extremists describe Shiites as rejectionists. The Safavids were an Iranian imperial dynasty of the 16th and 17th centuries.
"It has been revealed to the Islamic Umma (faithful) that he is just an instrument in the rejectionist Safavid plan that aims to spread the hegemony of the vali-e faqih," he said, referring to Iranian supreme leader Ayatollahi Ali Khamenei.
Zawahiri also hit out at continued "crimes" against Al-Qaeda suspects held at the Guantanamo Bay detention centre in Cuba under US President Barack Obama.
"America's tyranny, inflicted on the Muslims unjustly imprisoned for 13 years without charge, is a crime that has exposed the lie about freedom, human rights, democracy and peoples' rights that America claims," he said.
"The (hunger) strike of our jailed brothers exposes the real ugly face of America," he added.
Out of 166 inmates at Guantanamo, 80 detainees continue to refuse to eat in a protest that began more than five months ago. The number rose at one point to 106 inmates.