JERUSALEM (Reuters) - The Israeli army said on Wednesday it was reviewing a strike that harmed Lebanese troops in south Lebanon, an apparent reference to Israeli shelling that killed a Lebanese soldier and wounded three others the previous day.

"The Lebanese Armed Forces were not the target of the strike. The IDF expresses regret over the incident. The incident is under review," the Israeli military said in a statement.

Israel and the heavily armed Lebanese group Hezbollah have been exchanging fire across the Lebanese-Israeli border since the start of the war between the Palestinian group Hamas and Israel on Oct. 7.

The Lebanese army said the soldier, a sergeant, was killed when an army position was shelled by Israel on Tuesday.

The Israeli army said its soldiers had acted in "self defense to eliminate an imminent threat that had been identified from Lebanon" from a "known launch area and observation point" used by Hezbollah.

The U.N. peacekeeping force in Lebanon UNIFIL noted in a statement on Tuesday it was the first Lebanese army soldier killed during the hostilities, and that the Lebanese army had not engaged in conflict with Israel.

(Reporting by Jerusalem bureau; Editing by Tom Perry and Kim Coghill)