Schools were closed in the port city Wednesday after fighting broke out a day earlier between residents of two Tripoli neighborhoods, The (Beirut) Daily Star reported.
It was the seventh round of fighting to erupt between Jabal Mohsen, which supports Assad, and Assad opponents who live in Bab al-Tabbaneh.
Security sources told the Daily Star the number of wounded has risen to 48 since the fighting began.
The Lebanese Army stepped up its presence in Tripoli and vowed to respond to any gunfire, regardless of which side it comes from.
Prime Minister Najib Mikati urged residents of the city to stay calm and be wary of rumors and attempts to start trouble.
Tensions have been running high in Tripoli over reports a group of Salafist fighters from the city were killed by the military in the Syrian town of Tal Kalakh.