(AP) BEIRUT - Gunmen fired rocket-propelled grenades and machine guns early Monday in intense street battles in the Lebanese capital, wounding six people as fears mounted that the conflict in neighboring Syria was bleeding across the border.
The fighting appeared to be among the worst clashes in Beirut since 2008. The clashes erupted hours after an anti-Syrian cleric and his bodyguard were shot dead in northern Lebanon.
Lebanon and Syria share a complex web of political and sectarian ties and rivalries, which are easily enflamed. Last week, clashes sparked by the Syrian crisis killed at least eight people and wounded dozens in the northern city of Tripoli.
The revolt in Syria began 15 months ago, and there are fears the unrest will 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.
Sunday's fighting in Beirut pitted pro- and anti-Syrian Sunni groups, according to an Associated Press reporter at the scene in the Mazraa district. Gunmen were roaming the streets and several roads were blocked.
Lebanon's state-run National News Agency said gunmen were using "bombs and machine guns" and that six people were wounded.
The apparent trigger for the fighting was the shooting death of Sunni cleric Sheik Ahmed Abdul-Wahid and his bodyguard in northern Lebanon. The circumstances surrounding their deaths remain unclear but the NNA said they appeared to have been killed by soldiers after their convoy failed to stop at an army checkpoint.
The Lebanese army issued a statement, saying it deeply regretted the incident and that a committee will investigate.
The fighting underscores how the bloodshed in Syria, where President Bashar Assad's regime is cracking down on an uprising against his rule, is enflaming emotions in its tiny neighbor Lebanon. Lebanon has a fragile political faultline precisely over the issue of Syria.
There is an array of diehard pro-Syrian Lebanese parties and politicians, as well as support for the regime on the street level. There is an equally deep hatred of Assad among other Lebanese who fear Damascus is still calling the shots here. The two sides are the legacy of Syria's virtual rule over Lebanon from 1976 to 2005 and its continued influence since.
The fighting was the among the most intense fighting in Beirut since May 2008, when gunmen from the Shiite Hezbollah militant group swept through Sunni neighborhoods after the pro-Western government tried to dismantle the group's telecommunications network.
More than 80 people were killed in the 2008 violence, pushing the country to the brink of civil war.
There was no sign that Hezbollah was involved in the latest violence.
In Syria on Sunday, a roadside bomb exploded in a restive suburb of Damascus as senior U.N. officials toured the area on Sunday, the latest incident in which the unarmed observer mission has nearly been caught up in the country's bloodshed.
No casualties were reported in the blast, which detonated about 150 meters (500 feet) away from visiting U.N. peacekeeping chief Herve Ladsous and Maj. Gen. Robert Mood, the chief of U.N. observers in Syria. Journalists accompanying the team also were nearby. The explosion blew off the front of a parked vehicle.
A U.N. observer team with more than 250 members now on the ground has failed to quell the bloodshed in Syria, although it says it has had a "calming effect" in certain areas. Meanwhile, on several occasions, the team has come close to being caught in an attack, although there is no conclusive proof that it has been targeted.
Earlier this month, a bomb targeting an army truck exploded seconds after a convoy carrying Mood went past in the country's south. Last week, a roadside bomb damaged the mission's cars in a northern town just minutes after witnesses said regime forces gunned down mourners at a funeral procession nearby.
It was not immediately clear what the target of Sunday's explosion was, but the damaged car was parked near a security checkpoint in the suburb of Douma. A security official at the checkpoint told the U.N. observers that gunmen had targeted two military buses in Douma earlier in the day, wounding more than 30 security agents.
"We obviously don't have the specifics about what happened here this morning," Mood said Sunday.
Activists reported heavy shelling Sunday in the town of Soran in the central Hama province. The Britain-based Syrian Observatory for Human Rights called on the international observers to visit Soran and investigate reports of more than a dozen killed.
The revolt against Assad's regime started in March 2011 with mostly peaceful protests calling for political change. The deadly government crackdown led many opposition supporters to take up arms. Now, the regime is facing an armed insurgency targeting government installations, soldiers and security forces.
In March, the U.N. said that 9,000 people had been killed. Hundreds more have died since.
A cease-fire that was supposed to start last month has never really taken hold, undermining the rest of international envoy Kofi Annan's plan, which is supposed to lead to talks to end the 15-month crisis.
World powers remain divided on how to end Syria's crisis. The U.S. and other Western and Arab nations have called for Assad to leave power, and the U.S. and European Union have placed increasingly stiff sanctions on Damascus. But with Russia and China blocking significant new U.N. punishments, U.S. officials are trying to get consensus among other allies about ways to promote Assad's ouster.