At least 23 people have been killed since Sunday in Syria-linked clashes between Sunni and Alawite residents of the Lebanese port city of Tripoli, a security source told AFP on Friday.
Thursday was the bloodiest day yet in the clashes, with at least 11 people killed in 24 hours, the source said.
At least 167 people have been wounded in the clashes pitting gunmen in the Alawite Jabal Mohsen neighbourhood against those in the adjacent Sunni Muslim Bab el-Tebbaneh district.
The violence is tied to the conflict in Syria, where a Sunni-led uprising is fighting to overthrow the regime of President Bashar al-Assad, an Alawite.
The latest round of violence began as Assad's troops launched an assault against the rebel stronghold of Qusayr in Syria's central province of Homs.
The fighting in Tripoli, which has flared sporadically since the beginning of the Syria conflict in March 2011, has been largely confined to the two neighbourhoods.
Elsewhere in the city of 500,000 people, life has continued as normal to some extent, but with traffic lighter than usual and schools closed but most shops still open.
Inside Jabal Mohsen and Bab el-Tebbaneh, in the city's northwest, streets are abandoned, and some residents have fled their homes.
Troops have been deployed across the city since the outbreak, but neither their presence nor several meetings between top local leaders and security chiefs have managed to halt the fighting.
On Friday morning the fighting appeared to have subsided, but it was unclear if that was a precursor to a restoration of calm, or simply the usual lull before fighting resumed in the afternoon.