Hezbollah Chief Sayyed Hasan Nasrallah's nephew was killed in Syria during battles with rebel groups, media reports said Saturday, The Daily Star reported.
The resistance group issued a statement, saying Hamzah Yassine from the southern town of Abbasieh was killed while performing his "Jihadist duty defending Holy sites."
Local media reports including Al-Mustaqbal newspaper said Yassine was the son of Nasrallah's sister.
Hezbollah, alongside regime troops, have been engaged in fierce battles with rebel groups including Nusra Front in Syria and along Lebanon's border since May of last year, when the party announced its military role in the war-torn country.
On Friday, a Syrian jet strike on the border with Lebanon killed around 20 Syrian rebel fighters, security sources told Reuters. The strike hit just inside Lebanese territory in a barren area east of the town of Arsal.
Syrian rebel fighters have frequently crossed into Arsal, a Sunni Muslim town where residents have often been sympathetic to fighters trying to topple Syrian President Bashar Assad, who is from Syria's Alawite minority.