Militants carrying out an attack on an Israeli jeep last week penetrated hundreds of meters into Israel from Lebanon, military authorities now believe.

The terrorists managed to bypass border security and infiltrate deep into Israeli territory before they planted two small IED bombs in front of the jeep in the Friday attack, news site Walla reported Tuesday, citing military sources.

The Friday blasts, which took place in the Har Dov area in the north, damaged the jeep and caused light injuries to its occupants. Three soldiers were taken to a hospital to rule out any internal injuries from the blast, according to Israel Radio.

The blast was originally reported to have taken place along the border.

On Friday in retaliation for the attack, the IDF fired on several targets across the Lebanese border, including tank fire at a Hezbollah position in the village Kfar Kileh.

According to the report, the IDF investigation into the cross-border attack is ongoing.The incident is considered extremely serious due to the apparent security breach along the tightly controlled border which enabled the operatives to enter Israel, and the potential for further terror attacks or operations the breach represents.

Hezbollah was initially considered the most likely culprit behind the attack, although later Friday the Islamic State of Iraq and the Levant (ISIL), an al-Qaeda-linked group active in the Syrian opposition, claimed responsibility via Twitter. ISIL has been fighting against Hezbollah and the Bashar Assad regime in Syria, with clashes and targeted bombings spilling over into Lebanon in recent months.