Overnight clashes in Beirut between Sunni Muslim groups that support and oppose the regime in Damascus left one person dead and 10 wounded as fears rose further of a spillover from the Syrian conflict, Lebanese security officials said Monday.

The violence in the predominantly Sunni neighborhood of Tariq Jadidah was among Beirut's worst in the past four years. It erupted hours after an anti-Syrian cleric and his bodyguard were shot dead at a checkpoint in northern Lebanon, an incident that instantly spiked tensions even as far as the Lebanese capital.

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 UN estimates the conflict has killed more than 9,000 people since March 2011.

The circumstances surrounding Sunday's shooting death of Sunni cleric Sheik Ahmed Abdul-Wahid and his bodyguard in northern Lebanon remained unclear but the state-run National News Agency said they appeared to have been killed by soldiers after their convoy failed to stop at an army checkpoint. The cleric's funeral was scheduled for later Monday in the northern region of Akkar.

The Lebanese army on Sunday issued a statement, saying it deeply regretted the incident and that a committee will investigate.

The clashes in Beirut subsided around 4 a.m. Monday after anti-Syrian gunmen took control of the headquarters of the pro-Syrian Arab Movement Party.

Residents in the neighborhood said the streets were mostly empty Monday morning as many parents did not send children to schools and some shops did not open. Security officials, speaking on condition of anonymity in line with regulations, said that the man who was killed was a member of the Arab Movement Party.

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 die-hard 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 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.