At least four people were wounded on Wednesday in clashes between the army and residents of two areas of Lebanon's city of Tripoli supporting opposite sides in the crisis in neighbouring Syria, a security official said.
The official, speaking on condition of anonymity, said shooting broke out after soldiers tried to remove barricades in the northern port city's sensitive and mainly Sunni Muslim neighbourhood of Bab al-Tebbaneh.
Residents opened fire on the soldiers, one of whom was wounded, and the troops responded.
The clashes then escalated with residents of Jabal Mohsen, which sits opposite Bab al-Tebbaneh, also opening fire.
There were also reports of sniper fire.
Jabal Mohsen is populated mainly by Alawites loyal to the embattled regime of Syrian President Bashar al-Assad, while Bab al-Tebbaneh residents support the opposition seeking to oust Assad.
Clashes between residents of the two neighbourhoods earlier this week left nine people dead and some 50 wounded.