Abu Murtada al-Moussawi answered the call last summer from Iraq’s top Shiite cleric to help save the country from the Islamic State group, but after less than three months on the front lines he and several friends returned home because they had run out of food.

A triple suicide bombing Sunday killed at least 58 people in Iraq as a roadside bomb killed the police chief of the western Anbar province, authorities said, attacks that dealt major blows to Iraqi security forces struggling to combat the Islamic State extremist group.