New Delhi, Feb. 7 -- Pakistani counter-terrorism units conducted several raids and detained four individuals, among them the purported coordinator, linked to a suicide strike at a Shiite mosque on the capital's fringes that claimed 31 lives, interior minister Mohsin Naqvi announced on Saturday.

The declaration by Naqvi followed a day after a regional branch of the Islamic State, calling itself Islamic State in Pakistan, asserted its involvement via a bulletin on its Amaq News Agency. The report stated that on Friday, the assailant launched an armed assault on security personnel at the primary entrance before triggering his suicide vest upon arriving at the sanctuary's interior portal.

The IS organization indicated it considers Pakistani...