Saudi 10-Kilometer "Kill Zone" in Yemen?

Well, well. A week ago I noted that the artillery shown in a Saudi picture shelling Yemen had about an 11 or 12 kilometer range, and yesterday I remarked on the fact that Prince Khalid bin Sultan was talking about a 10-mile deep zone inside Yemen Saudi Arabia wanted clear of Houthis, though he never suggested Saudi troops might violate the border. Well, now a "Saudi government advisor" is telling Reuters that the Saudis are using air power and artillery "to enforce a 10-kilometer wide buffer zone inside Yemen." While the Saudis still deny having any ground forces across the border, I'd read that as acknowledging that they're bombing in the 10km strip south of the border.