BEIRUT (AP) -- Shooting between Sunni and Shiite Muslim gunmen in southern Lebanon killed three people and wounded at least five Sunday, officials said, in the latest sign Syria's civil war may be spilling over to Lebanon.
The clash between followers of hardline Sunni cleric Sheik Ahmad al-Assir and members of the Shiite militant group Hezbollah broke out after Shiite religious banners were raised in the port city of Sidon, the officials added. The banners marked Ashoura, an annual 10-day mourning period for Shiites that begins Thursday.
Sectarian tensions related to the conflict in neighboring Syria have been rising in Lebanon, coming to a head last month with the assassination of a senior anti-Syrian intelligence official. The killing of Brig. Gen. Wissam al-Hassan, a Sunni Muslim, sparked sectarian violence that killed at least 13 people.
Lebanon and Syria share similar sectarian divides that have fed tensions in both countries. Most of Lebanon's Sunnis have backed Syria's mainly Sunni rebels, while Lebanese Shiites tend to back President Bashar Assad, who belongs to the minority Alawite sect -- an offshoot of Shiite Islam.
The officials, who spoke on condition of anonymity in line with regulations, said al-Assir's bodyguard and a supporter were killed in the shooting, while the wounded included a Hezbollah commander.
An Egyptian boy who happened to be in the area was also killed, they said.
Shortly afterward, a Lebanese army force arrived in the Taameer area in Sidon, on the edge of the Palestinian refugee camp Ein el-Hilweh, to split the two groups apart.
Prime Minister Najib Mikati called for calm and self-restraint, saying on Twitter that no one should be allowed to cause security problems "during this sensitive period."
Interior Minister Marwan Charbel, a former police general, headed to Sidon where he met with security commanders in Lebanon's third largest city.
"The army will open fire at any person carrying weapons," Charbel warned before entering the meeting, adding: "No one is immune."
Al-Assir has become one of Lebanon's harshest critics of Hezbollah and Assad, and has repeatedly called for the militant group's disarmament.
Earlier this year, al-Assir and his supporters set up tents blocking a main road in Sidon for 35 days as part of an ongoing sit-in protesting the fact that Iran-backed Hezbollah maintains a formidable weapons arsenal.
The arsenal of Hezbollah, which fought a month-long war against Israel in 2006, is a divisive issue in Lebanon. Many opposition politicians are calling for the group's disarmament.
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.