Aviation officials in Swiss and Israel say a bomb threat on board an El Al flight bound from New York to Tel Aviv led France and Switzerland to deploy military jets as escorts, though the plane was continuing on its journey.

Spokesman Vladi Barrosa of the Swiss government-run air navigation service Skyguide said the plane left Swiss airspace into Austrian airspace.

In Israel, El Al spokeswoman Dana Hermann said "an anonymous tip was received. The flight is continues as planned to Tel Aviv."

The incident caused concern among locals in German-speaking Switzerland after two sonic booms echoed after two Swiss F/A-18 aircraft were deployed for the escort.

Barrosa said French military jets had also escorted the flight prior to its entry into Swiss airspace, but did not have further details.