The paramilitary force carried out targeted raids in several areas including Sohrab Goth, settlements near Memon Hospital, Macharr, Colony, Janjaal Goth and Kunwari Colony.
The suspects have been shifted to undisclosed location for interrogation.
Read here: Karachi bus attack death toll rises to 43, IS pamphlets found
Pistol-wielding gunmen in Karachi today stormed a bus carrying members of the Ismaili minority, killing at least 43 in the first attack in the country officially claimed by the Islamic State group.
The IS claims, posted on Twitter, are set to raise fears over the Middle East-based jihadists’ growing influence after they announced in January the creation of a branch in what they called “Khorasan province”, encompassing Afghanistan, Pakistan and parts of surrounding countries.