A poster of Syrian President Bashar al-Assad (left) with Hezbollah leader Hassan Nasrallah. Photo: Wikipedia.

A key figure and founder of Hezbollah’s military wing was killed today (Sunday) during a battle with rebel fighters in north-western Syria, Israel’s Channel 2 reported.

According to the Israeli site, Hassan Hussein al-Haj is the most senior commander of the Palestinian terror group based in Lebanon to have been killed since the organization’s entry into the years-long civil war in Syria.

Lebanese media reports say that al-Haj joined the Syrian army’s forces in the framework of the military expansion to Hama and Idlib that began Friday. The battle in which he was killed was an attempt by Syrian regime forces to re-occupy the village of Mansoura, in the Hama region.

According to Channel 2, sources in Hezbollah and Iran have confirmed the death of al-Haj, who headed Hezbollah operations in Syria. His killing, according to the report, is the second tough blow to the Iranian-Syrian coalition in the last two days, the first one being the killing of Iranian Revolutionary Guard Corps Brigadier General Hossein Hamedani by ISIS.