The facts so far are that the bomb, apparently not detonated by a suicide bomber, exploded at a central Jerusalem bus stop, injuring dozens and killing one woman. Prime Minister Netanyahu delayed a planned trip to Moscow (from which President Abbas—yes, to bury a lede, both Bibi and Abbas were going to be in Moscow at the same time—condemned the bombing, as did Prime Minister Salam Fayyad.
The explosion comes in the context of escalating Israeli-Palestinian tensions, prompted both by the Fogel family murders a week-and-a-half ago as well as a rare burst of mortar fire from Gaza this weekend, followed by a continuing series of rocket attacks from Gaza through today, accompanied by Israeli retaliations. Jerusalem last experienced a suicide-bomb attack in 2004, though it has sustained several other terrorist incidents since then. Attacking Jerusalem buses conjures bad memories and an incredibly direct threat to Israeli civic life, and will doubtfully go unanswered.