(Updates death toll rises, RPGs used, army cuts roads)
By Nazih Saddiq
TRIPOLI, Lebanon, Dec 4 (Reuters) - Two men were killed and 12 wounded in sectarian clashes in the Lebanese port city of Tripoli on Tuesday between gunmen loyal to opposing sides in neighbouring Syria's civil war, residents said.
The army cut off all roads leading to the area on Tuesday evening as militants launched rocket-propelled grenades at each other along Syria Street, a main thoroughfare that has become synonymous with fighting over the past year.
Tensions had been building since the deaths of at least 14 Lebanese and Palestinian gunmen from north Lebanon in a Syrian town close to the border. They appeared to have joined insurgents waging a 20-month-old revolt against Syrian President Bashar al-Assad.
Syrian state television has shown graphic footage of the dead men, riddled with gunshot wounds and lying in the grass.
Lebanon's Foreign Minister Adnan Mansour asked the Syrian ambassador to hand over the bodies of the men after their families protested in Tripoli to demand the Lebanese government return the dead and determine the whereabouts of the missing.
Tripoli's sectarian divisions have made it a flashpoint within Lebanon where violence from Syria has sometimes spilled over. The Syrian uprising is mostly being waged by Sunni Muslims and largely opposed by minorities like Assad's own Alawite sect.
Tripoli is a majority Sunni city and mostly supports the uprising next door, but the coastal city has an Alawite minority and clashes have erupted several times since the revolt began.
Residents said violence flared overnight when rocket-propelled grenades were fired by gunmen in the Sunni neighbourhood of Bab al-Tabbaneh and the Alawite area of Jabal Mohsen.
Fighting then broke out on Tuesday morning after Sunni gunmen approached some Alawite shops.
(Additional reporting by Oliver Holmes and Laila Bassam in Beirut; Writing by Oliver Holmes; Editing by Jon Hemming)