A worshipper at the Shiite mosque in Pakistan’s Islamabad, where dozens of people were killed in a suicide blast on Friday, described an “extremely powerful” explosion ripping through the building just after prayers started. Muhammad Kazim, 52, said he arrived at the Imam Bargah Qasr-e-Khadijatul Kubra mosque shortly after 1pm on Friday and took up a place around seven or eight rows from the imam. “During the first bow of the namaz [prayer ritual], we heard gunfire,” he said outside the Pakistan...