JERUSALEM (JTA) — Four Israel Defense Forces soldiers were injured by an explosive detonated as they patrolled the border with Lebanon.

The soldiers were taken to a hospital in northern Israel, where three underwent surgery and one was admitted to the intensive care unit.

The IDF Spokesperson’s Unit said it was investigating the early Wednesday morning incident, and said the IDF would continue to secure the northern border.

Lebanese media said that the explosion occurred inside the Lebanese border, with some reports putting it at 150 meters inside Lebanon and others at 6 meters. Blood stains and a hole are visible at the site of the explosion, according to Lebanese reports.

“There’s something that unites the south and the north and all our other fronts – the IDF soldiers who defend us and our borders,” Netanyahu said Wednesday. “That’s what happened last night. We’ll continue to act responsibly to protect Israel’s borders.”