The deadliest of the attacks occurred in ethnically mixed areas in the country's north.
On December 17, at least seven people were killed and 11 wounded in a bombing in Muafaqiyah, a village near the northern city of Mosul.
Also in the north, two car bombs went off in the town of Tuz Khurmato, killing at least five people and wounding 24.
The northern areas, with a population of Arabs, Turkomans, and Kurds, have recently been the focus of tensions between Iraq's central government and the semiautonomous Kurdistan region.
In the religiously mixed town of Baquba, north of Baghdad, roadside bombs killed at least one person and wounded about 10 others.
It was not immediately clear who was behind the December 17 attacks.