Four IDF soldiers sustained light to moderate injuries near the Lebanese border as a result of an explosion on Wednesday.
The soldiers were taken to a hospital in Nahariya. Three are undergoing surgery and one is in the intensive care unit.
The border area has largely been calm since the end of the Second Lebanon War seven years ago.
Lebanese media reported of two blasts in the Naqoura region followed by sounds of gun fire on Wednesday morning. It was further reported that the IDF fired illumination bombs in the border area.
Hezbollah's Al-Manar TV reported that the explosion was on the Lebanese side, six meters from the border.
A security source said traces of blood were found near a hole in the road adjacent to the al-Labouna area.
However, a Lebanese security source told local radio that the blast occurred when an IDF patrol infiltrated 150 meters deep into Lebanon.
The IDF's Spokesperson's Unit said in response, "The IDF is investigating the event and monitoring developments. We shall continue to secure the northern border." No other details were available.
Israeli troops deployed along the northern border have been on heightened alert since Syria's civil war began to spillover into Israel and Hezbollah became involved in the fighting.