A pilot stabbed a fellow crew member aboard a Flydubai flight en route from Dubai to Tel Aviv, Israeli Prime Minister Benjamin Netanyahu said.
Passengers and crew overpowered the attacker, regained control of the aircraft and landed it safely at Tabuk airport in northwestern Saudi Arabia, with more than 170 people on board.
The passengers, most of whom were Israeli, arrived early Wednesday in Tel Aviv on a repatriation flight.
The stabbed pilot, identified as Indian national Captain Smit Machchhar, was taken to hospital and reported to be in a stable condition. Netanyahu praised him as a "true hero" of "extraordinary bravery".
"Despite being stabbed and seriously injured, he fought back, resisted, opened the cockpit door, and enabled passengers and crew to overpower the attacker — preventing a catastrophic mid-air disaster," Netanyahu wrote on X.
"He saved the lives of 174 people, including Israeli citizens and other nationals."
The Indian embassy in Saudi Arabia confirmed Machchhar was in stable condition in hospital.
No motive for the incident has been established and the attacker remains under investigation in Saudi Arabia, Netanyahu told Fox News on Wednesday night, adding that the suspect is expected to be returned to the United Arab Emirates, where the flight originated.
Israel is likely to assist with the investigation, the prime minister said.
US President Donald Trump said he had spoken with Netanyahu about the event, describing the attacker as "perhaps a terrorist" or suggesting other possible motives.
Israeli Defence Minister Israel Katz also labelled the episode an "attempted jihadist terror attack", without offering further details.
Flydubai flight FZ1073 departed Dubai International Airport at 03:05 GMT (07:05 local time) bound for Ben‑Gurion Airport in Israel.
Approximately two and a half hours into the journey, flight‑tracking site Flightradar24 recorded a rapid descent over Saudi Arabia, with the aircraft losing more than 17,000 feet (over 5,000 metres) in under two minutes.
Minutes later the plane transmitted an emergency squawk 7700, then switched to squawk 7500, indicating a hijacking.
Around twenty minutes after those codes were sent, the aircraft looped back into Saudi Arabia and began a manual descent for landing.
Less than an hour afterward it reverted to squawk 7700.
Shortly after the incident, Israeli and Saudi Arabian air forces dispatched fighter jets while Netanyahu held urgent consultations.
Early media reports suggested a fight between the two pilots had caused the sudden drop and landing