Thousands of supporters of the Shiite Hezbollah movement protested on Saturday in the southern Lebanese town of Bint Jbeil against a film mocking Islam.
"This film that insults the Prophet is not merely a trivial creation carried out by a group, but American politics intended to be disseminated to the Western world," Hezbollah parliamentary representative Nawaf al-Moussawi told the crowd.
Women in black chadors carried colourful Islamist flags alongside young children holding the Koran, the Muslim holy book.
Moussawi ruled out a backlash against Christians in multi-confessional Lebanon, saying: "We participated with our Christian brothers wholeheartedly in the mass given by Pope Benedict XVI."
Several participants held posters of Hezbollah chief Hassan Nasrallah alongside pictures of Syrian President Bashar al-Assad, whose ruling clan hails from the Alawite sect, an offshoot of Shiism.
Some attacked Sunni cleric Sheikh Ahmed al-Assir, who has gained notoriety over the past year for his anti-Damascus stance.
"This Sheikh who instructs Muslims on the right path, what did he do for the south and for Lebanon? Did he say a word condemning the Israeli attacks?" asked demonstrator Mohammed Ali Bazzi.
"His every move was to disarm the resistance (Hezbollah), which is Israel's first demand," he told AFP.
On Friday, Sheikh Assir held his own smaller rally in Beirut, where participants waved Syrian revolution flags, alongside Islamic flags and a large Turkish flag.
Lebanon is deeply divided between a Western-backed opposition, which supports the Syrian revolt, and the ruling majority led by Hezbollah, which is staunchly pro-Damascus.