The Lebanese army has brought tanks and commando forces into the northern city of Tripoli, where fighting with suspected ISIL- and al-Qaeda-inspired fighters has intensified and spread to nearby areas.

Several tanks, armoured personnel carriers and Humvees carrying commandos arrived on the edge of the Bab al-Tabbaneh area on Sunday, where clashes were heaviest over the weekend.

The clashes, which broke out first on Friday night, have so far killed 10 soldiers, two civilians and wounded many others.

Fighting was also heavy around the town's old souq area, after which Lebanese soldiers began house searches looking for "ISIL suspects".

Troops on Wednesday killed three fighters and arrested a local leader in a raid in the northern Dinniyeh region, setting off the spark that led to the Tripoli fighting.

The Lebanese army said that troops attacked a school in the nearby town of Bhannine that fighters were using. It said several were wounded while others fled, adding that troops found two cars rigged with explosives as well as weapons.

The army said troops are deploying in Bab al-Tabbaneh and responding to the gunfire "of terrorists".

The state-run National News Agency said the troops were now in full control of Tripoli's northern suburb of Minyeh after arresting several fighters.

Fighters inspired by al-Qaeda and ISIL have killed and wounded several soldiers in a string of attacks in recent months.

The deadliest was in August, when fighters from Syria briefly overran the Lebanese border town of Arsal, capturing some 20 policemen and soldiers and killing several others.

That attack was the most serious spillover of the civil war into neighboring Syria since the uprising there began in March 2011.