Police officials said a car bomb exploded on a commercial street in the Shiite city of Diwaniyah, killing six people and wounding 16.
A car bomb blast near a bus stop in the holy Shiite city of Karbala killed three people and wounded 12, police said.
A third car bomb exploded near a restaurant in the holy city of Najaf, killing five people and wounding 12, according to the police.
Shortly before sunset, a bomb explosion killed three people and wounded 14 near restaurants in the Shiite part of Baghdad's southwestern district of Bayaa.
Sunni insurgents have long targeted Shiite areas with car bombs and other attacks. In June the Sunni extremist group calling itself the Islamic State seized large areas of northern and western Iraq. Its advance stalled when it approached Shiite-majority areas further south.