BEIRUT — The Lebanese army says an explosion overnight wounded Israeli soldiers who had crossed the border into Lebanon.

The army says in a statement that the Israeli force reached as far as 400 meters (yards) inside Lebanon in a rare incident along the volatile frontier.

The statement says the army is investigating the nature of Wednesday's explosion, which occurred in the area of Labbouneh near the coastal town of Naqoura.

The Israeli military said earlier that an explosion near Israel's northern border wounded four soldiers.

Israel fought a month-long war with the Iranian-backed Lebanese group Hezbollah in 2006 and sometimes there are cross-border attacks.