The bomb went off on Wednesday morning when a group of people, including servicemen, were boarding a bus.
Earlier reports said nine people were killed and at least 45 wounded
Lebanese President Michel Suleiman described the bombing as a terrorist attack and urged the security forces to track down those responsible as soon as possible. The Lebanese president was due to travel to Syria on Wednesday.
Over 20 people have lost their lives in Tripoli in recent months in violence linked to political tensions between Lebanon's Sunni-led governing coalition and an opposition alliance led by Shiite Hezbollah.
The attack occurred a day after a new national unity government, led by Prime Minister Fuad Saniora, won a vote of confidence. The new government was formed on July 11. No one has claimed responsibility for the attack.
