UAE investigators have said the co-pilot of a flydubai flight to Israel this week was planning a "terrorist act" and used the cockpit's emergency axe to attack the captain, but they did not reveal his motive.

During the flight on Wednesday, its Indian captain was assaulted by the co-pilot but managed to open the cockpit door, allowing passengers and crew to overpower the attacker and force an emergency landing in Saudi Arabia.

Initial findings from a UAE investigation did not disclose the co-pilot's nationality, according to a report Saturday (Oct 3) by the country's state news agency WAM, but a Saudi source has confirmed to AFP that he was Omani.

Media reports have also said he had been barred from flying in his home nation over concerns about extremist views.

The reports came as the first flight carrying Israelis home from the United Arab Emirates landed in Tel Aviv after services were suspended following the attack, according to Israel's airport authority.

"The co-pilot had attempted to carry out a terrorist act" and had "attacked the captain in the cockpit with the emergency axe and tried to take control of the aircraft", WAM quoted UAE Attorney General Hamad Saif Al Shamsi as saying, referring to initial findings of the investigation.

Passengers described rushing the cockpit and a fight for control after the plane plummeted -- losing around 17,000 feet of altitude in the span of a minute, according to the Flightradar24 website.

The wounded captain who opened the cockpit door has been hailed as a hero. On Saturday he was pictured with UAE Deputy Prime Minister Hamdan bin Mohammed during a visit by the leader to his hospital bedside.

The pilot Smit Machchhar embodied the "highest degrees of courage, responsibility, and care for human life", the UAE official said in a post on X.

The co-pilot meanwhile is in custody in the UAE. Multiple media outlets overnight identified him as Hamam al-Hammami and said he had been banned from flying in Oman over concerns about his extremist views.