Hezbollah leader Sheik Hassan Nasrallah, center, escorted by his bodyguards, waves to a crowd of tens of thousands of supporters during a rally denouncing an anti-Islam film in Beirut, Lebanon. (Hussein Malla/AP)

Tens of thousands of people hit the streets of Beirut to protest the controversial video mocking the prophet Muhammad on Monday, a massive rally organized by the Shiite Muslim militant group Hezbollah that was also an attempt to show the party’s strength.

Hassan Nasrallah, the leader of Hezbollah, made a rare public appearance around 6 p.m. local time and led the crowds in chants pledging martyrdom to the prophet Muhammad.

“The world should know our anger will not be a passing outburst but that this is the start of a serious movement that will continue all over the Muslim world to defend the Prophet of God,” he told the crowd, who roared their approval as he spoke. Nasrallah also warned the U.S. that if the full anti-Islam movie is released, rather than the short clip that has been posted on YouTube, there will be “dangerous consequences.” The video supposedly promotes a full-length film.

The U.S. Embassy, which is a roughly 30-minute drive away from central Beirut, has begun destroying classified documents as a security precaution, the Associated Press reported. The U.S. Embassy in Beirut was the target of a car bomb in 1983 that killed 63 people; the U.S. Marine barracks was also attacked by a car bomb the same year, an incident with 242 fatalities. 

Hezbollah’s militia has long been the strongest military force in Lebanon and fought a short but bloody war with Israel in 2006 that left at least 1,100 Lebanese dead. Many of the group’s supporters still consider that conflict to be a victory against the Israelis.

But the group also runs a strong political party and has members in parliament. The faction allied with Hezbollah — known as the March 8th Movement — is the governing coalition, and nominated the current prime minister, Najib Miqati, last year.

The demonstration Monday wound through streets in Beirut’s predominantly Shiite southern suburbs, a Hezbollah stronghold. Platforms and speakers had been set up and organizers stoked up the crowd with chants of “Death to America” and “Israel is the enemy of Muslims.”

 “If we keep silent about this movie, then this will happen again,” said Zeinab, a 40-year old housewife whose 7-year-old son was carrying a Hezbollah flag. “America is responsible. Whether it’s the people or the government. They are responsible.”

Protests against the controversial video flared up last Friday in Tripoli, the second-largest city in the Lebanon and one which is predominantly Sunni Muslim. The situation there veered out of control as demonstrators torched a Kentucky Fried Chicken restaurant and attempted to overrun a government building. One man was killed and more than a dozen were injured after protesters clashed with police.

 But Hezbollah supporters were noticeably absent from the streets of Beirut and the group’s leaders did not call for public demonstrations last Friday, which was the day Pope Benedict XVI arrived in the country for a three-day visit. Hezbollah appears to have shown restraint in keeping its supporters off the streets until Monday in order not to disrupt the pope’s visit, which ended on Sunday.

 It was also a savvy political move, analysts say, since Hezbollah is allied with the Free Patriotic Movement (FPM), a largely Christian party led by Michel Aoun. Hezbollah’s alliance with the FPM is a point the group’s leaders highlight to show that they have support beyond their mostly Shiite base. If Hezbollah had called for demonstrations during the pope’s visit, it would have probably irked their Christian political allies.

Thousands of supporters of the Shiite Amal party, who are allies of Hezbollah, also joined the demonstrations on Monday.

Hezbollah’s al-Manar television reported that a number of Christians had joined the crowds to condemn the controversial video. And some protesters also made an effort to show that the demonstration is not an attempt to antagonize Christians or start civil strife. One young woman carried a sign that read “Jesus and Mohammed are prophets. We do not target Christ.”

 But the rally wasn’t about the controversial video alone. In recent months, Hezbollah’s carefully cultivated image as a supporter of the downtrodden and symbol of resistance to Israel and the United States has been damaged as the group’s leaders have stood steadfastly by Syrian president Bashar al-Assad amid an increasingly bloody crackdown against opposition forces.

The rally Monday was also an attempt to show that the political alliance that many observers refer to as the “axis of resistance” — Hezbollah, Syria and Iran — is still holding strong. Demonstrators carried pictures of Assad and Syrian flags in the crowd on Monday, and some carried Iranian flags, too.

Hezbollah has called for demonstrations to continue and take place in other cities across Lebanon in coming days. Sunni leaders, not to be outdone by their Shiite counterparts, also announced more protests on Monday. The controversial Sunni sheikh Ahmad Assir, who is based in the city of Sidon, announced a demonstration for his followers later this week.