On Dec. 18, 2009, Houthi fighters in northern Yemen fired several artillery rockets across the border into Saudi Arabia, according to the supplied material. No casualties were recorded in what may have been the group's first cross-border projectile attack on the Kingdom.
The same account describes that strike as the opening salvo in a campaign of intermittent bombardment that, 17 years later, has claimed hundreds of innocent lives. Over that period, the account states, the sophistication and lethality of the Houthi missile arsenal have grown exponentially.