BEIRUT (AP) — The most serious fighting in Beirut since 2008 appears to have been touched off by a traffic dispute that escalated into deadly, hours-long street battles between the Shiite Hezbollah group and a small Sunni faction, witnesses said Wednesday.

Security officials and the state news agency said three Hezbollah members and a follower of the conservative Sunni al-Ahbash group were killed Tuesday night in the residential Bourj Abu Haider district, just outside Beirut's downtown, in running battles with fighters wielding assault rifles and rocket-propelled grenades.

Funerals for two of the victims were expected later Wednesday. The army said in a statement only three had died. The discrepancy could not immediately be explained.

It was also not clear why the fighting intensified so dramatically, but tensions among the Sunni and Shiite communities have been running high recently amid reports that Hezbollah members will be indicted in the 2005 assassination of former Prime Minister Rafik Hariri, once the country's top Sunni politician.

Abdul Qadir al-Fakhani, a spokesman for al-Ahbash, said his group was meeting with Hezbollah and the Lebanese army on Wednesday to ensure the situation does not flare up again.

Al-Fakhani and several other witnesses said there was a commotion outside the Bourj Abu Haider mosque about 20 minutes before the gunbattles began, with men fighting over a car.

"They were shouting and yelling insults at each other," al-Fakhani told The Associated Press. "Then a group from Hezbollah approached the mosque and they just kept coming. We were astonished," he said.

Within some 20 minutes, both sides apparently gathered reinforcements and the street battles began.

Hezbollah did not comment beyond a joint statement issued by the two groups late Tuesday saying the incident resulted from a "personal dispute and has no political or sectarian background."

The next morning, the mosque facade was peppered by bullets and grenades, and cleaning crews were sweeping up the rubble. At least one gunman holding an AK-47 assault rifle had taken up position in a building across from the mosque.

Two other witnesses and a Lebanese soldier — all of whom asked that their names not be used because of the sensitivity of the matter — independently corroborated al-Fakhani's account of a traffic dispute. Local media also reported witness accounts of a parking dispute preceding the clashes.

The fighting was the worst clash in Beirut since May 2008, when Hezbollah gunmen 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. But officials insisted Tuesday's clash was not the same sectarian strife that has bedeviled Lebanon for decades.

Lebanese President Michel Suleiman condemned the fighting and urged authorities to arrest those who were behind the shooting. The emir of Qatar, who brokered the "Doha Agreement" that put an end to the May 2008 fighting, called Suleiman on Tuesday night to offer any assistance, the president's office said.

Lebanon's government is an uneasy coalition of a Western-backed bloc and Hezbollah, which in just a few years has gained so much political power it now has a virtual veto over government decisions.

Al-Ahbash, or the Association of Islamic Charitable Projects, is a deeply conservative Muslim group and a rival to many other Sunni groups in the country, including the prime minister's Future movement.

The group's name rose to prominence in the wake of the Hariri assassination. Two senior officials from the group were detained for about four years on suspicion of involvement in the killing, but were later released.

Like Hezbollah, al-Ahbash is pro-Syrian. They have feuded in the past over theological differences but were political allies whose candidates ran on the same lists during the 2009 parliamentary elections.