By Nazih Saddiq
TRIPOLI, Lebanon (Reuters) - Clashes erupted between heavily-armed supporters and opponents of Syrian President Bashar al-Assad in Lebanon's port of Tripoli on Saturday, killing nine people and prompting Lebanese Prime Minister Najib Mikati to rush there to try to stop the violence.
Mikati held talks with ministers and officials in the northern city, as gunmen a few kilometers (miles) away fired machineguns and rocket-propelled grenades at each other. Residents and a doctor said 42 people had been wounded.
"The Lebanese army and internal security forces need to take all measures to stop the clashes in the city of Tripoli, without discrimination," a statement from Mikati's office said. The army moved into the area with armored vehicles but did not open fire, said a Reuters journalist at the scene.
The clashes began after midnight on Friday and were continuing late on Saturday when mortar bombs could be heard.
Gunmen from the Jabal Mohsen district, home to the minority Alawite sect - the same offshoot of Shi'ite Islam to which Assad belongs, have fought on-off skirmishes over the past few weeks with Sunni Muslim fighters in the Bab al-Tabbaneh area.
Saturday's death toll was the highest in a single day in Tripoli, raising fears that Syria's unrest could spill over into its smaller neighbor.
The Lebanese National News Agency said there was "shelling across both areas heard every five minutes, and snipers targeting civilians".
Residents said those killed included civilians caught in the crossfire and that a Lebanese soldier was among the wounded.
The areas have long-standing grievances separate from the Syrian conflict but the Sunni-led uprising against Assad has caused strife among Lebanon's mixed population, especially in majority Sunni Tripoli, 70 km (43 miles) north of Beirut.
Syria flooded Lebanon with troops early in its 1975-1991 civil war and dominated its neighbor for more than a decade afterwards. It retains significant influence over Lebanon's intelligence apparatus and military, despite having withdrawn troops in 2005.
International peace envoy Kofi Annan said on Saturday that Syria was slipping towards all-out civil war and that the entire region could suffer if the international community did not step up pressure on Assad.
"Let me appeal to all of you to engage earnestly and seriously with all other stakeholders, mindful that if regional and international divisions play out in Syria, the Syrian people and the region - your region - will pay the price," Annan told a meeting of Arab League member countries.
The United Nations says forces loyal to Assad have killed more than 9,000 people during the revolt in Syria.
(Additional reporting by Oliver Holmes in Beirut and Regan Doherty in Doha; Writing by Oliver Holmes; Editing by Ralph Gowling)