The father of a Lebanese soldier abducted and slain by militants two years ago has phoned a local TV to say he killed a relative of the man he holds responsible for his son's death.

The soldier, Mohammad Hamieh, and 36 other Lebanese soldiers were abducted by militants and Islamic State fighters from neighboring Syria in 2014. Hamieh and three other soldiers were later killed while 24 have since been released. The whereabouts of the remaining nine are unknown.

The slain soldier's father, Maarouf Hamieh, called in to Al-Jadeed TV on Tuesday to say he killed Mohammad Hujairi in an act of revenge, vowing he would continue killing others.

Hujairi is the nephew of an al-Qaida-linked local figure, Mustafa Hujairi, who in 2014 had promised to negotiate the soldiers' release.