Syrian uprising sparks sectarian clashes in Lebanon (AP) TRIPOLI, Lebanon - The uprising in Syria fueled intense clashes in neighboring Lebanon for a third day Monday, with gunmen firing assault rifles and rocket-propelled grenades as sectarian tensions spilled across the border. At least four people have been killed in Lebanon's second-largest city, Tripoli, since the gun battles erupted late Saturday. Lebanon and Syria share a complex web of political and sectarian ties and rivalries, which are easily enflamed. The revolt in Syria began 14 months ago, and there are fears the unrest could lead to a regional conflagration that could draw in neighboring countries. The U.N. estimates the conflict has killed more than 9,000 people since March 2011. Syria's violence relentless, crossing borders Militant video claims deadly Syria bombings Syria: Dozens killed in huge Damascus explosions Syria is overwhelmingly Sunni, but the country's President Bashar Assad and the ruling elite belong to the minority Alawite sect. The uprising has exacerbated Sunni-Alawite tensions in Lebanon, as well, sparking the clashes in the northern Lebanese city of Tripoli. The clashes began late Saturday after authorities detained Lebanese national Shadi Mawlawi, an outspoken critic of Assad. Military prosecutor Saqr Saqr charged Mawlawi on Monday and five others, including a Qatari, a Palestinian and a Jordanian with belonging to an armed group and carrying out armed acts inside and outside Lebanon, judicial officials said. The officials spoke on condition of anonymity because they were not allowed to speak to the media. The arrests apparently enraged the Sunni population supporting the uprising, and clashes soon erupted between Sunni fighters and Alawites who support Assad. A Lebanese Sunni family runs between white tarps hung to provide cover from snipers as they flee their house during clashes in the northern port city of Tripoli, Lebanon, Monday, May 14, 2012. Credit: AP Photo/Hussein Malla Tripoli's Bab al-Tabbani neighborhood is overwhelmingly Sunni and posters supporting the Syrian opposition hang on walls, and pictures of a local activist shot by a sniper in similar clashes in February read "Greetings to the free martyrs of Syria" and bear the Syrian revolutionary flag. The fighters are clear about the root of the conflict that has them shooting at their neighbors. Syria. It wants it this way. It wants to start a battle here so it can say, look, even in Lebanon the Sunnis are killing the Alawites," said Mustafa Nashar, 35, whose family lives in an apartment overlooking Syria Street, which cuts through the neighborhood. Groups of men, many of them carrying assault rifles and wearing military-style vests ducked Monday through trash-strewn alleys. The residents who have remained in the neighborhood take cues from fighters about when to sprint across alleys to evade the snipers up the hill. A car with children crouching in the back sped past one alley, a bullet pinging the pavement right behind it.