Lebanon's army said Monday that a suicide attacker who assaulted a checkpoint in the southern city of Sidon a day earlier was Palestinian.

An army officer was killed in the incident, as were two armed men who accompanied the attacker, who were gunned down by troops manning the checkpoint.

The army checkpoint was attacked late Sunday, shortly after another military post in the same city had been attacked by a man who hurled a hand grenade towards it. He too was shot dead by troops at the checkpoint.

"Bahaa Eddine al-Sayed, of Palestinian origin, got out of the car he was in while two others stayed inside. He approached soldier Tamer Rizk and detonated himself using a home-made bomb," the army said Monday.

"The soldier died, and two other troops were wounded," it said, adding that "other troops at the checkpoint opened fire at the car, killing the two Lebanese men Mohammad al-Zarif and Ibrahim al-Mir."

The army said troops found an explosive belt, detonators and bombs in the car.

Sidon, a majority Sunni city south of Beirut, was the scene of fierce battles in June that pitted the army against fighters loyal to a radical cleric, Ahmad al-Assir, who has since been on the run.

Assir is fiercely opposed to the powerful Shiite movement Hezbollah and its ally in Damascus, President Bashar al-Assad.

The June battle claimed the lives of 18 Lebanese troops and 11 fighters, and ended when the army seized control of Assir's compound in the city.