I have noticed one curious fact. Whenever, a bomb blast happens in a Mosque, the mosque under attack in Pakistan seems to be a Shia Mosque. This time also the story was not different. A Shia mosque was bombed in Shikharpur, in Sindh Province of Pakistan.
At least, sixty odd people died in the blast. It is widely propogated that Muslims do not follow a caste system. That is far from true. The war between Shia and Sunni sects have claimed more life than any feud.
I think, for Sunnis, Shias are lesser Muslims!
You can read about the ISIS link to the blast here.