In the north, near the city of Kirkuk, an army officer and a soldier were killed when two mortar shells struck a military camp, officials said.
And in the town of Latifiyah, 30 kilometers (20) miles) south of Baghdad, a mortar shell hit a group of Shiite pilgrims heading to the holy sites in the city of Karbala.
The pilgrims were commemorating Arbaeen, the end of 40 days of mourning following the anniversary of the death of Prophet Mohammed's grandson, Imam Hussein, a revered Shiite figure.
Hundreds of thousands of Shiite pilgrims make their way every year to Karbala for Arbaeen.