Israel closed the airspace in its North to civilian traffic following attacks on Syrian targets that were believed to be carried out by the Israeli military.
The closure comes after the Israeli military moved two Iron Dome missile defense batteries to northern Israel near Safed and Haifa on Sunday morning.
The Israeli domestic airline Arkia on Sunday canceled all flights from Haifa to Eilat for five days, saying in its statement that the closure was "due to IDF instructions on the closure of airspace in the North until May 9."
Meanwhile, White House spokesman Josh Earnest told reporters Sunday that President Obama believes "the Israelis are justifiably concerned about the threat posed by Hezbollah obtaining advanced weapons systems, including some long-range missiles." The U.S. "is in very close contact" with the Israeli government, Earnest said.
Syrian state media accused Israel of an early Sunday morning attack on what it identified as the Jamraya military research center located approximately 10 miles from the border with Lebanon.
The Reuters news agency cited an unnamed "Western intelligence source" on Sunday who confirmed the attack and said Israel targeted stores of long-range Fateh-110 missiles that were in transit from Iran to Hezbollah. The missiles have the capacity to strike Tel Aviv from Lebanon. Israel's military did not confirm nor deny reports that it was responsible for the attack.
Israel was said to be responsible for an attack on a Syrian target two days earlier; it has not confirmed or denied the attack.