A Wizz Air passenger flight from London Luton to Sofia was diverted to Budapest on Monday after a bomb threat was received while the aircraft was in the air, the airline and Hungarian officials said. A Hungarian Air Force Gripen fighter jet escorted the plane to a safe landing, and a security inspection later found nothing on board.

Source: Radio Bulgaria (BTA/MTI)

Flight 4302 had left Luton at 08:33 GMT and was due in the Bulgarian capital at 13:25 local time, according to flight-tracking data reported by the BBC. Instead, the Airbus A321neo changed course over Bosnia and Herzegovina, requested permission to land in Budapest and touched down at Liszt Ferenc International Airport at 12:09 local time (11:09 GMT).

Hungary's Defence Minister Romulusz Ruszin-Szendi said NATO's air defence readiness service issued an ALPHA alert and a Gripen took off from Kecskemet within minutes to escort the passenger aircraft. Once the plane was on the ground, the fighter returned to its base and police took over the response, he said.

Source: Air Data News

Wizz Air said the aircraft taxied to a designated stand, where authorities carried out security checks on the plane and its passengers. The airline said it was cooperating fully with the authorities and that the safety of passengers and crew was its highest priority.

Source: The Aviation Hub (LBC/Sky News)

The airline later confirmed the inspection had been completed and nothing was found, and the aircraft was set to depart again. No injuries were reported, and neither the airline nor Hungarian officials said how the threat was received or who made it.

Why fighter escorts happen

Fighter escorts are a standard NATO-member response when a civilian aircraft in controlled airspace is subject to a security threat: the military jet identifies and accompanies the airliner while civilian authorities prepare a secure landing. Bomb threats against commercial flights require a full response even though the vast majority prove to be hoaxes.