Its simply the people behind this attack like RAW, NATO and the US...who else?
When Pan-Islamists are destroying Pakistan, why would the Pan-Hinduist need to do anything. They will just sit back and watch Pakistan dismantled brick by brick all thanks to so called pakka-Muslims.
It is a well know fact that Wahabi Islam cannot tolerate Shia Islam and vise versa. Go to saudi and see how liberated Shias are, and similarly Iranian's elect Sunnis to be their leaders. NOT!
Pakistani dimwits especially Talibans and JI have imported Wahabi thoughts about the world and that includes hatred for Shias. And off course Shias have imported Iranian hatred for Abu bakar, Umar, and Usma rahs.
Knowing even a tiny bit about the lay of the Pakistani land, everyone knows that most of the explosions and killing of Shias in Pakistan is done by JI, Taliban, and other terrorists who follow Saudi and Egyptian wahabi style.
If you and all those taliban-apologists want to be shifty-crafty like Indian media, then go ahead and blame this Shia-Sunni tussle on RAW. That will be like burying head deep in the hot sand while Muslims kill Muslims. Shabash.