BAGHDAD (AP) — Attacks overnight in two Iraqi cities killed at least 16 people, officials said Monday as authorities struggle to stop the Sunni militants’ offensive that has left huge areas in northern and western Iraq outside of government control.

In one of the attacks, mortar rounds rained down on Shiite neighborhoods in the town of Mahmoudiya on Sunday night, killing 11 civilians and wounding 31, a police official said. The mixed Shiite-Sunni town is about 30 kilometers (20 miles) south of Baghdad.