The continued disruption of Global Positioning System signals in Israel’s airspace could be a result of Russian systems based on a ship in the Mediterranean Sea or on land at one of their military bases in Syria, Israeli defense officials said on Friday.

If the GPS disruption systems are based on land, then they are most likely located in northern Syria, they added.

However, officials also said they were examining the possibility that the disruptions, which have affected only airborne crews flying in and out of Tel Aviv's Ben Gurion Airport, originate in Israel. They believe that in such a case, there is no "malicious intent," and the operator is most likely unaware of the consequences.

In the case of Russia, too, officials are uncertain whether sabotage is intentional or if it is an accidental byproduct of the Russian military’s attempts to protect its forces at the Khmeimim Air Base in northwest Syria.

Officials noted the electronic systems are relatively cheap and mobile, causing them to believe disruptions are originating from areas of fighting in Syria. The devices, made by Ukranian companies and costing just $20,000 apiece, can disrupt GPS signals within a range of up to 500 kilometers. Similar systems are in use in Lebanon, officials said, but due to the country's topography, their range is limited and they are unlikely to be causing problems in Israeli airspace.

Open gallery view Ben Gurion Airport, Israel. Credit: Yaakov Saar / GPO

An Israeli cyber official said this is an exceptional incident because usually similar attacks take place in larger areas and for a shorter period of time. The decision to disrupt civilian airspace makes it much more likely that this is the intent of the operator, because if the attacker had wanted to interfere indiscriminately, the disruptions would have also affected terrestrial navigation, and not just in air.

On Thursday, Russia denied any responsibility for the disruptions: The Russian ambassador to Israel said on Army Radio on Thursday that the reports are “fake news,” and “can’t be taken seriously.”

Israel has been experiencing unexplained GPS disruptions in its airspace in the past month, but “measures are in place to allow safe landings and takeoffs” at its main international airport, the government said on Wednesday. The announcement by the Israel Airports Authority (IAA) followed a report on Tuesday by the International Federation of Air Line Pilots’ Associations (IFALPA) that “many” pilots had lost satellite signal from the GPS around Tel Aviv’s Ben Gurion Airport.

Confirming there had been GPS disruptions for approximately the past three weeks, an IAA statement said these affected only airborne crews and not terrestrial navigation systems. An aviation source told Haaretz the interruptions occur only during daytime, but “do not put pilots and passengers at risk.”