(CNN) Rare Kabul attack: Who did it and why?

(CNN) -- Tuesday's deadly suicide attack targeting Afghan Shia just didn't fit the pattern of what had come before in this troubled country.
The police formed the usual cordon at the attack site -- this time a shrine in Kabul. Sirens pierced the odd moment of eerie silence, but the police chief's face was contorted with fury and confusion, like he'd seen so...Continue Reading....