Sunni Muslim Salafist leader Ahmad al-Assir shaves his head during a sit-in in Sidon, southern Lebanon on July 4, 2012. Assir, a hard-line cleric, embodies the rise of conservative Sunni Islamists. (Ali Hashisho/Reuters)

From his mosque in southern Lebanon, Sheik Ahmad Assir, a hard-line cleric, embodies a new trend in the Middle East: the rise of conservative Sunni Islamists openly opposed to Shiite militants and their backers in Iran and Syria.

Assir, 44, has become Lebanon’s chief rabble-rouser by taunting Hezbollah, the Shiite militia and political party that is the most powerful group in the country, and calling its members “liars” and “criminals” during weekly Friday prayers, when hundreds gather to hear him speak.

“We have no more dignity or honor,” Assir said during a prayer meeting last week, banging a fist on a lectern. “They keep violating our pride, but we will make them pay. We will make them walk around like crazy people talking to themselves.”

The audience erupted into wild cheers and clapping.

Lebanon has long been the battleground for regional rivalries. Many Lebanese accuse Syria in the assassination of former prime minister Rafiq al-Hariri, a Sunni Muslim, in 2005, even though a U.N. investigation concluded that Hezbollah operatives carried out the attack.

As a result, the political scene has been defined by those who support Syria, primarily Hezbollah and its allies, and those who oppose Syria, including the majority of the Sunni community and their allies.

Assir is gaining a following among Lebanon’s Sunnis, who for years have felt threatened by Hezbollah’s well-trained militia and have been outmaneuvered in the country’s cutthroat politics. In the past two weeks, Assir has ratcheted up the pressure with a sit-in blocking a key access road in Sidon, his home town, to demand that the government confront Hezbollah over its arms caches.

Now, the uprising in neighboring Syria is bringing the tensions to a head. The conflict in Syria is becoming more of a sectarian battle as the opposition, which is predominantly Sunni, struggles to oust a regime dominated by Alawites, members of a religious sect that is an offshoot of Shiite Islam. Lebanese Sunnis understand that the ouster of Syrian President Bashar al-Assad could significantly weaken Hezbollah, Syria’s closest ally in Lebanon, and they are speaking out forcefully in support of the opposition.

And no one is speaking out more brazenly and more frequently than Assir, who has held anti-Assad rallies that draw large crowds.

“The Islamists in the region think they have to move now with the Muslim Brotherhood in Tunisia, Egypt and now Syria. They feel it’s their time to rise up. Assir is trying to do this in Lebanon,” said Mohammad Obeid, a Shiite intellectual and former member of the Amal party.

A shift from secular mold

Unlike in Egypt and Syria, the Muslim Brotherhood and hard-line religious groups have traditionally not been the leaders of the Sunni community in Lebanon. Most Lebanese Sunni leaders after the 1975-1990 civil war have been relatively secular and pro-Western. Assir’s popularity signals a shift away from that mold.

Assir’s formula for success has been simple: denounce Hezbollah and other Shiite parties as often as possible and accuse them of being pawns of Syria. He has even taken personal shots at Hasan Nasrallah, Hezbollah’s leader, a red line rarely crossed in Lebanon’s highly charged sectarian political environment.

Assir calls the group “Hizb-u-Muqawama,” the party of resistance, rather than “Hizb-u-Allah,” the party of God, refusing to associate the name of God with any party. “Nasrallah’s grand speeches and weapons make him seem like a king or a pharaoh. This makes his people very arrogant,” Assir, wearing a simple gray robe, white skull cap and silver-rimmed glasses, said in an interview.

“The same axis that’s ruling Lebanon is ruling Syria. And we’re suffering the same as the Syrian people are suffering,” he said. Some critics have accused Assir of helping smuggle weapons to Syria’s armed rebels, but he says that his supporters are not armed and that he has no role in sending weapons to the Free Syrian Army.

The anti-Hezbollah sit-in that began June 29 features a ramshackle collection of tents and canvas coverings spread across half a mile. It is guarded by unarmed men with walkie-talkies and caps emblazoned with the word “endhibat,” or security.

Inside the camp, most men sport shaved heads and long beards, a style favored by ultraconservative Salafists, and most of the women are covered head to toe in black. Many participants have clustered around a Suzuki dealership.

“The sheik is confronting the biggest problem facing the Sunni community and all of Lebanon,” said Ahmad Sabayoun, a 26-year-old cellphone salesman wearing a Puma sport shirt, shorts and running shoes. “He always says and does the right thing.”

‘Dangerous’ provocateur

Assir’s provocation comes at a particularly sensitive time. Sectarian clashes in recent months in the northern city of Tripoli and in Beirut, the capital, have been linked to the uprising in Syria. The fighting has killed more than two dozen people.

Part of the reason Assir has enjoyed a measure of success is that there is a lack of leadership in the Sunni community.

Former prime minister Saad Hariri, son of the slain former premier, has not been in Lebanon for more than a year. When Hariri broke his leg while skiing in the French Alps in January, Assir didn’t miss the opportunity to take a jab, telling a television interviewer that Hariri was neither a good leader for the Sunnis, nor a good skier.

There is little in Assir’s background that would suggest a path toward religious radicalism or politics. He was born to a lower-income family in Sidon. His father was a well-known singer and his mother is Shiite, both attributes that would be frowned upon by Sunni religious hard-liners. At age 17, when Lebanon was in the midst of the vicious civil war, Assir gravitated toward religion. He discovered that he had a gift for public speaking and developed a following within a decade.

But it has been Assir’s provocative sectarian statements that have gained him the most notoriety and, perhaps, the most support. In an interview with al-Jadeed TV on June 24, Assir openly criticized Nasrallah and Nabih Berri, the speaker of parliament and the head of the Amal party. Hezbollah did not respond to Assir’s statements.

The following day, gunmen firebombed the TV station with molotov cocktails and blasted it with Kalashnikovs. When Lebanese security forces arrested one of the gunmen two days later, dozens more hit the streets across Beirut, burning tires and firing machine guns in the air.

“Assir can be dangerous,’’ said a former senior Lebanese security official who spoke on the condition of anonymity because of the sensitivity of the issue.

“When there is a conflict, the extremists will always rise and the moderates will go down.’’