After three months of fighting near the Israeli-Lebanese border, Israel struck a significant blow to the organization on Monday when it killed a key Hezbollah leader in a hit in south Lebanon, according to people familiar with the group’s activities.

According to a top source in Lebanon, Wissam Tawil was the commander of Hezbollah’s elite Radwan forces and the most senior Hezbollah official to be murdered in the battle. He also played a crucial role in leading the organization’s activities in the south.

Since Hamas, the group’s Palestinian ally, assaulted Israel from Gaza on October 7, more than 130 Hezbollah fighters—including members of Radwan—have died in the fighting, sparking a war that has spread throughout the area.

With Israel conducting air and artillery attacks and Hezbollah firing guided missiles and other weaponry at Israeli positions, it has been the worst conflict between Israel and the Iran-backed group since their war began in 2006.

On both sides of the boundary, tens of thousands of people have fled, and the violence has sparked fears of a more significant battle. According to three sources in Lebanon, Tawil and another Hezbollah member were murdered when the car they were riding in was hit near the Majdal Selm hamlet, around 6 kilometers (3.7 miles) from the border.

Israel refrained from commenting right away. Images showing Tawil with prominent figures from the heavily armed Shi’ite Muslim organization, such as Secretary General Sayyed Hassan Nasrallah and its military commander, Imad Mughniyeh, who was assassinated in Syria in 2008, were shared by Hezbollah.

In another picture, he was seated next to Qassem Soleimani, the late commander of the Iranian Revolutionary Guards’ Quds Force, who was assassinated four years ago in Baghdad by an American drone attack.

Tawil’s death, according to the senior source, was a significant blow considering his background, which included Hezbollah deployments in Iraq and Syria.

Hezbollah asserts that its current conflict with Israel aims to defend Palestinians in the Gaza Strip, which has been subject to an Israeli assault since a strike by Hamas on October 7. The majority of the fighting between Israel and Hezbollah has been restricted to regions close to the Israeli-Lebanese border.

When an Israeli attack killed deputy Hamas commander Saleh al-Arouri in a Hezbollah-controlled section of Beirut’s southern suburbs last week, tensions increased. Israel has not acknowledged or refuted allegations that it was responsible for the strike.

In a “preliminary response” to Arouri’s death, Hezbollah said on Saturday that it had launched 62 missiles toward a significant Israeli observation station.

One of the other Radwan Force members slain in the fighting was Abbas Raad, a prominent Hezbollah politician’s son. In November, he was murdered in an Israeli attack.

Sayyed Hassan Nasrallah, the secretary-general of Hezbollah, cautioned Israel not to go all out for a full-scale war on Lebanon in two broadcast speeches last week. “Whoever thinks of war with us—in one word, he will regret it,” Nasrallah stated.

According to Naim Qassem, the deputy commander of Hezbollah, the organization does not wish to “initiate total war, but if Israel decides to wage total war on us, then we in the field will respond with total war without hesitation and with all we have” on Sunday.

Since the start of hostilities, nineteen Hezbollah militants have lost their lives in Syria. Iran-aligned organizations from all across the area have been involved in the Hamas-Israel conflict. For example, the Houthis from Yemen have fired on ships in the Red Sea and launched missiles and drones toward Israel. At the same time, militias backed by Tehran have attacked American soldiers in Iraq and Syria.