Two people have been killed and a dozen more wounded as rival camps clashed in the streets of the northern Lebanese city of Tripoli.
The causalities included a Palestinian nurse who was gunned down by sniper fire.
A security official noted that the Lebanese army has been ordered to increase patrols and arrest anyone who threatens public security. The troops are ordered to use force if necessary.
Tripoli unrest appears to be the deadliest incident in Lebanon since the Doha peace deal came into effect a month ago.
The power sharing deal was reached between rival factions so as to end political crisis that resulted in deadly clashes in May, which raised fears of a return to all-out civil war.
Clashes between opposition and pro-government groups erupted two weeks ago in the northern port city. The latest development, takes the number of casualties to 11.
MP/MMN