At least 120 Hezbollah fighters have died in clashes between Syrian rebels and government forces near a town north of Damascus in recent days, an opposition group claimed late Sunday.

According to the Syrian Observatory for Human Rights, some 120 fighters from the Shiite terror group were killed around the town of Yabroud, where government forces have been battling to retake the area from rebels near the border with Lebanon.

Syrian state TV reported that government forces killed 15 rebel fighters and injured at least 70.

The death toll for Hezbollah would be one of the highest for the Lebanese group since it entered the war over a year ago to bolster the forces of embattled Syrian President Bashar Assad, reportedly at the insistence of Iran, a patron state for both Syria and Hezbollah.

Yabroud, a rebel holdout on a supply route in the Qalamoun mountains, between the Lebanese border and capital Damascus, has been pounded from the air by Syrian barrel bombs for the last several weeks in a renewed offensive to take the town. Hezbollah fighters have also reportedly poured into the area to back Syrian government forces.

It was not clear from the Observatory’s report when the Hezbollah members were killed and there was no independent confirmation of the death toll.

According to the Lebanese Daily Star, Hezbollah recently said 15 of its fighters died while performing their “jihadist duties” in March. The paper cited a website affiliated with Hezbollah saying that the Lebanese Shiite militia had lost 40 soldiers in the month-long siege of Yabroud as of March 7.

Pro-rebel Al-Gad TV reported that at least 200 government and Hezbollah fighters died in the battle to capture Yabroud in recent weeks.

Hezbollah has lost several fighters in the Syrian civil war while fighting for its ally, Syrian President Bashar Assad. The Syrian Observatory for Human Rights reported in February 2014 that since entering the conflict in late 2012, the Shiite group had lost 275 men.

The three-year Syrian civil war has left over 140,000 people dead and forced millions of civilians to flee their homes.