Saudi Arabia and a coalition of mostly Gulf Arab states intervened in Yemen’s civil war in 2015 to try and push back the Houthis after the movement drove the internationally recognized government into Saudi exile.
The coalition has launched thousands of air strikes which have hit schools, markets and hospitals, killing hundreds of people – though it says it does not target civilians.
The Houthis have stepped up ballistic missile attacks on the kingdom in what it says is retaliation for the air raids.
They have frequently claimed attacks, including on Aramco facilities, that Saudi Arabia and its main ally the United Arab Emirates have either said did not happen or were intercepted.
The group unveiled what it said was a series of drones, including the Qasef-1, at a ceremony last year.
The arms monitor Conflict Armament Research (CAR) said it had evidence showing the Qasef-1 and other Houthi kit was made in Iran and was not of indigenous design and construction “in contrast to Houthi statements”.
The coalition accuses the Houthis of being armed and supported by Iran – charges the group and Tehran deny.