Suspected Islamic State bombers assassinated an Iraqi provincial police chief and killed 28 people in an attack on a Kurdish security headquarters on Sunday, a second straight day of mass attacks that killed scores.

The two attacks, in the north of the country and the west, showed the jihadist group’s ability to inflict damage on both the forces of the autonomous Kurdish region and the central government, despite U.S.-led air strikes.

Islamic State claimed responsibility for the suicide bombing of a Kurdish security compound in the north, saying it had sent three foreign bombers: a German, a Saudi and a Turk, according to SITE, a group that monitors jihadi announcements. […]