Tripoli, 30 kilometers (20 miles) from the Syrian border, has been the scene of violence fueled by sectarian tensions.
The Lebanese army used "rockets" for the first time to quell the fighting between rival neighborhoods, one security source said, without specifying which weapons were used. Normally, soldiers use assault rifles to target snipers.
The sources said three of the dead belonged to Bab al-Tabbaneh district and two others killed were from the neighborhood of Jebel Mohsen.
Clashes between fighters in Bab al-Tabbaneh and Jebel Mohsen have flared several times in recent months, killing dozens since the beginning of the year.
RA/NJF