Mohammad Aslam Khan, head of Karachi counter-terrorism cell, told the BBC that the attack was "clearly targeted" at the Bohra Ismaili Shia community, from which most of the dead and injured came.

BBC: Pakistan attacks: Bombs strike Quetta and Karachi

The chief of the Pakistani Taliban in Karachi, Khan Zaman Mehsud, recently fled to Waziristan, Mr. Aslam, the counterterrorism police officer, said.

WSJ: Taliban Thrive in Pakistani Commercial Hub