An Israeli police forensic expert works at the scene after a blast on a bus in Jerusalem, April 18, 2016.
(photo credit: REUTERS)
The terrorist bomb that tore through a Jerusalem bus on Monday is just the type of attack that security forces, led by the Shin Bet (Israel Security Agency) domestic intelligence agency, have been working intensively for months to try and prevent.
Security forces are looking the possibility that the bomber is among one of the seriously wounded in hospital.
Beyond that fact, they are maintaining a fog of secrecy around their investigation into the bombing, and key questions remain unanswered, at least in the public domain, at this stage.
These include the question of whether the attacker acted alone,was part of small, amateur cell, or whether an organized terrorism cell, sent and funded by one of the established Palestinian armed factions, is behind the atrocity.
Additionally, it remains unclear whether the attack occurred when it did because the bomb went off prematurely, or whether a suicide bomber detonated an explosive device.
The bombing confirms warnings aired by security sources in recent days, who said that the coming Passover holiday could see 'the unstable respite' shattered by terrorism.
Behind the scenes, the Shin Bet quietly foiled many Hamas large-scale terrorism plots that were surfacing in the West Bank recently, often stopping them at a late stage, just before the attackers could strike.
Hamas in Gaza has not stopped trying to remotely orchestrate terrorism in the West Bank and in east Jerusalem. It is prepared to risk its truce with Israel in Gaza, which is valuable to it, to pull off a major attack in an Israeli city.
Monday's blast could represent one of the rare occasions when such an organized plot bypassed Israel's extensive intelligence networks - networks that are usually able to deliver a warning in time to stop acts of murder.
The other option, that of a small, amateur local cell being behind the attack, would mean that it was able to use its obscurity and low profile to slip under the Shin Bet's considerable radar.
Security forces are in a race against time to get to the answers, and prevent the reappearance of mass violence on Israeli streets