Police officials say a car bomb exploded on a commercial street in the Shiite city of Diwaniyah, killing six people and wounding 16 others. Diwaniyah is 130 kilometers (80 miles) south of Baghdad.
Police later said a car bomb blast near a bus stop in the holy Shiite city of Karbala killed three people and wounded 12 others.
Medical officials confirmed the casualties. All officials spoke on condition of anonymity because they were not authorized to speak to journalists.
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.