TRIPOLI (REUTERS) - A soldier and a civilian were killed in fighting between Sunni Muslims and Alawites in the northern Lebanese city of Tripoli, bringing the death toll from four days of clashes to 12, security and medical sources said.

The civilian was killed by sniper fire and the soldier when militants fired rocket-propelled grenades at two personnel carriers that had been dispatched to quell the violence on Saturday night.

Tensions between the Sunni Muslim majority and small Alawite community in Lebanon's second city have festered for decades, but the long-standing rivalry has worsened because of the sectarian war raging in neighbouring Syria, where a Sunni-led uprising is seeking to overthrow the Alawite president.

At least 70 people, including 17 Lebanese soldiers, have been wounded in clashes which broke out on Thursday after gunmen fatally shot a Sunni man who had Alawite relatives and lived in a mostly Alawite area of the city.

The fighting had eased up on Sunday but snipers were still operating around Syria Street, which separates the Alawite enclave of Jabal Mohsen from the Sunni district of Bab al-Tabbaneh.