The United Arab Emirates, UAE says the co-pilot who attacked the captain of a Flydubai flight bound for Israel used a cockpit emergency axe in an attempted terrorist attack.

Prosecutor General Hamad Saif Al Shamsi said Saturday that the co-pilot assaulted the captain and tried to take control of the aircraft. Investigators are still examining his motives.

The attack unfolded Wednesday during the Dubai-to-Tel Aviv flight, which was carrying more than 170 people.

As the co-pilot attacked the captain, the aircraft plunged more than 16,000 feet in just over 30 seconds, according to flight-tracking data. Despite being injured, the captain managed to open the cockpit door, allowing passengers and crew to intervene and overpower the attacker.

One passenger said he helped steady the aircraft using knowledge gained from watching an air-crash television programme.

With the attacker restrained, off-duty pilots took control of the aircraft and landed safely in Tabuk, Saudi Arabia.

The suspect was detained in Saudi Arabia and transferred to the UAE on Thursday. Israeli investigators are expected to participate in the UAE-led investigation.

Reuters has identified the co-pilot as Hammam al-Hammami, an Omani national, citing two sources however Emirati authorities and Flydubai have not publicly confirmed his identity.

The injured captain, Smit Machchhar, later described his struggle to get help during the attack.

Speaking from a hospital bed in Abu Dhabi during a video call with Indian Prime Minister Narendra Modi on Friday, Machchhar said he knew the aircraft was descending and forced himself to open the cockpit door despite his injuries.

Modi praised Machchhar for his courage and presence of mind.

Hamam al-Hammami allegedly used a crash axe in the attack.