The source told AFP the strike took place near Quneitra, close to the ceasefire line separating the Syrian part of the Golan Heights from the Israeli-occupied sector, confirming a report by Lebanon's Al-Manar television.
The source could not provide details about the identities of the targets or the nature of the attack they were allegedly preparing.
The Israeli army would not comment.
According to the source, Israeli drones were present in the area during the attack. Last month, the Syrian army said it shot down an Israeli reconnaissance drone flying over Quneitra province.
Syria and Israel are officially in a state of war, and Israel has occupied the Golan Heights since 1967. The occupation is not recognised by the international community.