Syria's civil war threatens to escalate into regional sectarian conflict
Calls for jihad grow as proxy war between Gulf states and Iran threatens to destabilise region
The Egyptian cleric was in a fervour. As Hezbollah's Shiite fighters helped Bashar Assad to crush Syrian rebels, he wanted to sound the alarm to Sunnis across the Middle East.
"Now is the time for jihad," he insisted.
Speaking on a Saudi TV station, Sheik Mohammed el-Zoghbi called on "young men in Egypt, Libya, Tunisia, Algeria, Kuwait, Jordan [and] Yemen" to go to Syria to fight.
"We must all go to purge Syria of this infidel regime, with its Shiites who came from Iran, southern Lebanon and Iraq," he shouted on Al-Khalijiya TV.
The overt entry by Lebanon's Hezbollah militia into Syria's civil war on the side of President Assad, has sharpened sectarian divisions across the Middle East.
Fighters from the Shiite guerrilla group helped Syrian forces batter the rebel-held town of Qusair for three weeks until they finally overran it last week in a significant victory for Assad's regime. Many Sunni hardliners have taken Hezbollah's intervention as a declaration of war by Shiites against Sunnis.
That could have dangerous implications for the entire region.
Calls for jihad by Sunni clerics could increase the flow of foreign militants into Syria to fight alongside the rebels. Sunni Arab powers like Saudi Arabia and other Gulf countries, who see the war as a way to break the influence of Assad's Shiite ally Iran, may boost weapons supplies to Syria's rebels to counter Hezbollah.
Already several thousand foreign militants - from across the Arab world and as far away as Chechnya and Somalia - are believed to be fighting among the rebels. Some have close ties to al-Qaeda. That has been a major reason the United States is reluctant to help arm the resistance.
It could also fuel conflict neighbouring countries. Hezbollah's intervention in Syria threatens to bring the war even further into Lebanon, where rebels have vowed to retaliate with attacks on the Shiite group's home turf. It has also enraged Sunnis in Lebanon, who resent Hezbollah's political domination there.
On Friday, the acting head of the Syrian National Council said the possibility of a sectarian war meant the West should act.
"The problem will be widespread all over the Middle East," George Sabra said. "The international community should act now. Otherwise it will be a real [ sic] dangerous conflict between Sunnis and Shias."
On a geopolitical level, Syria's war has morphed into a proxy fight. Shiite Iran has strongly backed Assad, but Sunni Arab nations have backed the rebels in hopes that Assad's fall would break the alliance that gives Iran influence in the Arab world.
Now those using the region's heightened sectarian divide are portraying it as an outright religious fight between the two main sects of Islam, which split in the 7th century in a dispute over who should lead Muslims after the Prophet Mohammed died.
Hezbollah has depicted its role in the war in sectarian terms, saying it must defend against takfiris - a term for Sunni radicals.
On Salafi TV stations and in sermons, Sunni clerics have stepped up their denunciations of Shiites and called for action.
"The Sunnis have to wake up from their coma," Egyptian Sheik Osama Suleiman said on a Salafi talk show last month. "This is what the Shiites are, this is their hidden wickedness."