"Two Israeli raids hit a Hezbollah target on the border of Lebanon and Syria," the source said. The Syrian Observatory for Human Rights said the target was a Hezbollah "missile base".
Residents of Nabi Chit, on the Lebanese side of the border, told AFP they saw flare bombs light up the sky ahead of the raids yesterday, which shook their houses.
Residents in neighbouring areas said they heard planes flying low before the raids.
Nabi Chit is a bastion of Hezbollah, which is helping the Syrian regime battle insurgents. The Shiite group has a suspected weapons store and training camp there.
Israel did not immediately confirm or deny responsibility for the raids.