The Lebanese army says it has arrested a man belonging to a "terrorist" organization as he was trying to flee Lebanon on a fake passport.

An army statement issued Friday said Ali Ahmad Laqqis, a Syrian national known as Abu Aisha, was a member of the al-Qaida branch in Syria known as the Nusra Front. It described him as "dangerous" and said Laqqis confessed to killing a kidnapped Lebanese soldier last year.

The soldier, Mohammad Hamieh, is among some 20 policemen and soldiers who were abducted by the Islamic State group and Nusra Front during a brief cross-border raid on the Lebanese border town of Arsal last year.

The extremists have killed four of them and are still holding the rest.