Hours before the flight, the airline said on its Facebook page that "it has not yet received operating permits," and expressed "deep regret to the travelers for not being allowed to operate."

A diplomatic crisis broke out last October after the then-information minister George Kordahi was quoted criticizing the Saudi role in Yemen, prompting the kingdom and other Gulf allies to expel Lebanese envoys.

Saudi energy ministry said the pre-dawn attack on the refinery in Riyadh caused a small fire that was brought under control. The ministry called the attack an act of "sabotage and terrorism".

Fragments fell to the ground after the interception of the drone over Abha International Airport, which has previously been targeted in similar assaults by the Houthi rebels. The injured included citizens of Bangladesh, India, Nepal, the Philippines and Sri Lanka as well as two Saudis.

The deployment, to "assist the UAE against the current threat", follows a phone call between Defense Secretary Lloyd Austin and Abu Dhabi Crown Prince Mohammed bin Zayed Al-Nahyan. The UAE suffered its third missile attack in consecutive weeks on Monday.

A UAE-trained militia said Saturday some of its fighters remained on the front lines in key Yemeni conflict zones as part of defensive measures after driving out the Houthi rebels.

Omani mediators appear to be convincing the Huthis to accept a ceasefire and take part in peace negotiations