According to Lebanese media, the alleged site of the second attack had chemical weapons manufactured there.
The last full-blown armed conflict between Israel and its northern neighbors took place in 2006, as Israel carried out a military operation against Hezbollah and its infrastructure in Lebanon.
On Wednesday, Lebanese media reported that Israeli fighter jets crossed over into Lebanese air space for several hours Tuesday night.
Earlier in the week, the Israeli army deployed Iron Dome anti- missile batteries in the north, amid the tension in the northern borders.
On Sunday's weekly cabinet meeting, Israeli Prime Minister Benjamin Netanyahu warned cabinet members of the risks of Syrian chemical weapons making their way to Hezbollah.
IAF commander Maj.-Gen. Amir Eshel reiterated Tuesday Netanyahu 's sentiments. "Nobody has any idea what's going to happen in Syria," Eshel said, "This is happening in a place with a huge weapons arsenal, some of which are not conventional."
In 2007, a mysterious attack on a site deemed to be a nuclear reactor in Syria was attributed to Israel, which did not formally acknowledge any connection to it.
According to Israel Radio, despite the recent developments, no security measures were taken in northern Israeli cities and bomb shelters remain closed.