TRIPOLI, Lebanon, Aug 13 (Reuters) - A bomb targeted a bus in the northern Lebanese city of Tripoli on Wednesday, killing at least nine people, including seven soldiers, security sources said.

At least seven more people were wounded by the bomb, which was planted either inside the civilian bus, or just by it and exploded in a busy district of Lebanon's second largest city.

Lebanese security forces fought Sunni Islamist militants in Tripoli last year at the start of a insurrection by the al Qaeda-inspired Fatah al-Islam group, which was based at the nearby Nahr al-Bared Palestinian refugee camp.

The army lost 170 soldiers in the fighting.

Lebanese President Michel Suleiman, who was army chief during the Nahr al-Bared fighting, is scheduled to visit Damascus later on Wednesday to meet Syrian President Bashar al-Assad.