ERBIL, Kurdistan Region of Iraq – Israeli Prime Minister Benjamin Netanyahu on Friday pledged to impose a “very heavy price” on whoever was behind an alleged attempt to take control of a flydubai flight bound for Tel Aviv.

The incident occurred Wednesday when the flight’s co-pilot allegedly stabbed the captain and attempted to take control of the aircraft, prompting passengers and crew to intervene. The plane was diverted and made an emergency landing in Saudi Arabia.

“The attacker had undergone Islamist radicalization; he intended to crash the plane, along with its passengers,” Netanyahu said, praising those who intervened for preventing a “9/11-type disaster.”

“We are currently investigating whether he was sent by others, and whoever sent him will pay a very heavy price,” Netanyahu said.

The Israeli premier gave a hero's welcome to the passengers who helped stop the attack and reroute the plane, as well as Indian national Smit Machchhar, the flight’s captain.

According to Flightradar24, the plane lost around 17,000 feet of altitude in the span of a minute.

One passenger who rushed to intervene during the attack, 50-year-old Yaniv Hayun, said he had learned how to stabilize a nosediving plane from a TV show. He made the remarks during a meeting with Netanyahu, in a video distributed by the Israeli premier’s office.

The UAE on Thursday announced that it had launched an investigation into the incident, probing a possible “terrorist” link to the attack.

Operator flydubai said all 174 passengers, including 166 Israelis, were safe.

US President Donald Trump said it “seems as though the co-pilot was perhaps a terrorist or perhaps a whack-job” after discussing the incident with Netanyahu.