A senior Hezbollah commander is said to have been killed in a battle between rebel forces and the Syrian army, The Times of Israel reported.

Marwan Mughniyeh, whose cousin Imad Mughniyeh was assassinated by an alleged Mossad-CIA operation, died after fierce fighting in the Qalamoun region, northeast of Damascus, Syrian opposition sources reported.

The Qalamoun region is located near the Syria-Lebanon border and was a major rebel stronghold until last year.

According to the sources, Mughniyeh was in charge of special operations for the Lebanese Hezbollah terror group, which is currently fighting alongside Syrian President Bashar Assad.

Over the last several weeks, fighting between Syrian and rebel forces has increased dramatically with spillover inside Israel.

On April 28, air raid sirens alerted residents of northern Israel of incoming rockets, followed by the sounds of explosions along the Golan Heights. After an IDF investigation, the army declared that Syrian mortars did indeed explode inside Israeli territory but were spillover from fighting between Syrian and rebel forces.

As the fighting continues, Hezbollah’s leader Hassan Nasrallah announced a victory for the group. Speaking on Al-Manar television on Saturday, Nasrallah stated that Hezbollah and Syrian forces had taken control of the largest Al-Nusra Front’s base in the Qalamoun region at Sahlet al-Maaysra.

Nasrallah has made clear that his group’s future is now dependent on the future success or failure of Assad. In a recent meeting with political allies, Nasrallah expressed his concern that Syria may not be able to fully recover from the ongoing civil war and “highlighted the necessity of fighting…by all means to protect Lebanon and its stability.”