US President Donald Trump has warned that Iran would face a severe response if investigations establish that Tehran was linked to an incident involving a co-pilot who allegedly attacked the pilot of a Flydubai flight travelling from Dubai to Israel.

The incident occurred on Wednesday, with passengers reportedly helping to overpower the co-pilot after the aircraft lost significant altitude. The plane subsequently made an emergency landing in Saudi Arabia before the passengers were flown back to Israel.

Speaking to reporters at the White House on Thursday, Trump said he believed Iran could be linked to the incident, although he acknowledged that investigations were still ongoing.

Asked whether the United States would retaliate against Iran if it was found responsible, Trump said, “Oh, they’ll be hit very hard, don’t worry.”

The United Arab Emirates has opened an investigation into the incident, including whether it involved terrorism.

Saudi Arabia said the co-pilot was transferred to the UAE on Thursday, accompanied by an Emirati security team. Its initial investigation indicated that the co-pilot had attacked the aircraft’s captain.

Israeli Prime Minister Benjamin Netanyahu described the incident as an attempted terrorist attack and alleged that the co-pilot had undergone Islamist radical indoctrination.

Netanyahu identified the co-pilot as an Omani national and said Israel would participate in the investigation led by the UAE.

He also praised the aircraft’s captain, Smit Machchhar, an Indian national, and passengers who intervened during the incident.

Passengers said they rushed towards the cockpit after the aircraft suddenly lost altitude, with Flightradar24 data indicating that the plane dropped about 17,000 feet within a minute.

The injured captain was later visited by the Indian ambassador to the UAE. The Indian Embassy said he was in good health and recovering.

Indian Prime Minister Narendra Modi also praised Machchhar as a “HERO” for his actions.

Meanwhile, Flydubai said another crew member who was travelling on the flight landed the aircraft safely and announced the suspension of its flights to Israel while investigations continue.

The incident comes amid increased US military activity in the Middle East. Axios reported that the United States had deployed additional Patriot missile batteries to Saudi Arabia and Qatar and that the USS Theodore Roosevelt aircraft carrier and its strike group were heading towards the region.

The UAE investigation is expected to determine the circumstances surrounding the incident, including the motive of the co-pilot and whether it was connected to any terrorist activity or external actors.