TRIPOLI, Lebanon - One person was killed and six were wounded in fresh clashes early Friday in Lebanon's northern port city of Tripoli, a security official told AFP.

He said the person died and two people were wounded when a vehicle refused to stop at an army roadblock in the largely Sunni district of Bab al-Tebbaneh. The army had stepped up its security measures and was on alert after a grenade explosion in Bab al-Tebbaneh.

Soldiers opened fire after the driver refused to stop. An exchange of fire between fighters from Bab al-Tebbaneh and troops of the internal security forces resulted in four soldiers wounded, one seriously.

Fighting and grenade blasts are commonplace between the neighbouring districts of Bab al-Tebbaneh -- where most residents are Sunni supporters of Western-backed Prime Minister Fuad Siniora -- and Jabal Mohsen, a largely pro-opposition area of Alawites who support Syria and the Hezbollah movement.

Fourteen people have been killed and more than 100 wounded since June in clashes between the two neighbourhoods.

Calm had returned last week after the army moved in, threatening to riposte against any security threats.