Official reports don't seem completely consistent so far; perhaps this is just the natural confusion of reporting on an unanticipated event (remember the wild reports on 9/11). As a commenter who knows the Gulf well noted in a previous post, reports have said that the suicide bomber detonated himself only a meter from the Prince, yet the Prince suffered only minor injuries to his left hand, and there were no other casualties except the bomber, supposedly blown to bits. The photo of the Prince meeting with the King in the hospital afterwards (above left) has only one visible sign of injury: the middle finger of his left hand is bandaged and there's a splint or something similar showing. A picture today, greeting Pakistan's Interior Minister, shows the same: just a big bandage on the middle finger of the left hand. (Second photo.)
Several reports in Arabic have said the bomb went off during taftish, "inspection," presumably a security checkpoint. Is security only a meter away from the Prince, or is the one-meter story attempting to make the attempt sound like it got closer than it did? What kind of explosion can tear the bomber's body apart (according to some reports) but only injure the middle finger of a man a meter away? Some reports have said that the bomb was triggered by a cell phone call; one suggested it might have even been hidden inside the bomber's body. Still, it's hard to picture the geography of all this. If it was a security checkpoint, why were no security men injured, or were they and this has been suppressed? (As far as I've seen, the only casualties are supposed to be the bomber and the Prince's middle finger.) Now, if the man was not armed with a suicide vest or triggered by a cell phone call but was, say, carrying a simple hand grenade, this might be more credible, if his clothing somehow provided containment for the blast (though in Jidda in August I doubt he was wearing a leather coat or anything similar that might impede the shrapnel). Another report says he was "seated to the left" of the Prince, which doesn't seem fully consistent with the other accounts.
The narrative is gradually filling out. Since many readers don't read Arabic this Saudi Gazette article today is a good summary. Note that Yemen is implicated; the bomber (still unnamed) and his brother are among the most wanted men in the Kingdom; he entered from Yemen (from Ma'rib in southern Yemen, an area until recently claimed by Saudi Arabia), and despite his coming in from southern Yemen the article manages to bring in the Houthi campaign in northern Yemen as well. I found this odd:
[The] attack raises concerns that Yemen’s instability could allow Al-Qaeda to carry out cross-border attacks. The Yemeni army is on a near three-week-long offensive on strongholds of Zaidi rebels, also known as Huthis, in lawless swathes around Saada city in the Mareb region.Sa‘da and Ma'rib, assuming that's what "Mareb" refers to, aren't anywhere near each other.
So the story is still emerging. I'm not sure when we'll have a clear narrative (if we ever do), but it's quite clear that the Saudis are going to use this to further their campaign against terrorism and to evoke popular sympathy and outrage.