The soldiers were trying to detain Khaled al-Tallawi, who heads a "militant cell" behind the August 21 murder of two police officers and the son of the mayor of Kaftoun village in the country's north, the army said.

Tallawi opened fire and lobbed a hand grenade at the troops who raided his home in the Beddawi area near the northern port city of Tripoli late Sunday, it added.

Three soldiers were killed on the spot while another was severely wounded and later succumbed to his injuries.

The army said that Tallawi was later shot dead after soldiers chased him and affiliated militants in a hunt that lasted into the early hours of Monday morning.

Troops are still searching for other members of Tallawi's cell, the army said.

Lebanese security forces have been chasing suspects over the Kaftoun murders for weeks.

Police had already arrested a suspect in the Beddawi camp for Palestinian refugees near the northern port city of Tripoli, the day after the killings.