Saudi authorities have issued a precautionary emergency alert in the capital, Riyadh, urging residents to follow safety instructions and take shelter.
Residents have been advised to remain in safe places inside buildings, stay away from windows and avoid open areas.
Those outdoors have been urged to seek shelter in the nearest building. If that is not possible, they have been instructed to take cover behind a solid structure.
Saudi authorities have yet to provide details about the threat or situation that prompted the emergency alert.