Demonstrators protesting caricatures of Islam's prophet set fire Sunday to a building housing the Danish mission in Beirut. Security forces shot tear gas into the crowd and fired their weapons in the air in a desperate attempt to stop the onslaught. In Beirut's Christian neighborhood, rioters stoned churches as the violence threatened to take a sectarian spin. Security officials said at least 30 people were injured, including policemen, fire fighters and protesters, as demonstrators rioted against cartoons originally published in the Danish newspaper Jyllands-Posten. Orange flames and thick, gray smoke were seen billowing from the 10-story building, which also houses the Austrian Embassy and Slovak consulate, as firefighters struggled to put out the flames. Protesters waved green flags from the broken windows of the building and threw papers and filing cabinets from the windows as firefighters tried to get them out. Medics pulled an unconscious man from the building. A police official said he was a protester who was overcome by the smoke. Casualties, fires and damage of public property were reported in the violence, which came a day after protesters in neighboring Syria torched the Danish and Norwegian embassies in Damascus. In Lebanon, a scheduled protest quickly degenerated into violence when groups of Islamic extremists tried to break through the security barrier, prompting troops to fire tear gas and water cannons from fire engines to try to disperse them, said the official. Troops also fired repeatedly in the air to keep the protesters away. The government called for an emergency Cabinet meeting to be held later Sunday. The Danish Foreign Ministry urged Danes to leave Lebanon as soon as possible. It had also advised its citizens to leave Syria the day before. Grand Mufti Mohammed Rashid Kabbani denounced the violence and blamed infiltrators among the protesters whose aim was to "harm the stability of Lebanon." Speaking on Future TV, he appealed for calm and said there were some who were trying to "exploit" the protests to cause trouble and "distort the image of Islam." The trouble, in the main Christian area of Ashrafieh, threatened to take a sectarian spin, especially after the protesters began stoning the nearby St. Maroun Church, one of the city's main Maronite Catholic churches, and private property. Muslim clerics on the scene were seen trying to stop the protesters using shields and their hands. Any tension with sectarian flavor is a sensitive issue in Lebanon, where Muslims and Christian fought a 15-year civil war that ended in 1990. The demonstrators also attacked policemen with stones and set fire to several fire engines, witnesses said. Black smoke was seen billowing from the area. They also burned Danish flags. President Emile Lahoud denounced the violence and said "national unity should remain protected and consolidated." He warned against attempts to destabilize the country. "Those who are committing these acts have nothing to do with Islam or with Lebanon," said Prime Minister Fuad Saniora. "This is absolutely not the way we express our opinions." A security official, who spoke on condition of anonymity because he was not allowed to speak to the press, said embassy staff had evacuated the building along with their belongings and documents two days ago, in anticipation of protests. The violent protest comes a day after thousands of protesters in neighboring Syria, Damascus set fire to the Danish and Norwegian embassies in the most violent in days of furious protests by Muslims in Asia, Europe and the Middle East.