Attacks across Iraq on Sunday killed 31 people, police officials told the Associated Press.
The officials spoke on the condition of anonymity, being unauthorized to speak to the press, but the AP said medical personnel had confirmed the figure.
Reuters said at least 10 people had been killed in the attacks on Sunday, which come days ahead of the major Muslim feast of Eid al-Adha.
Police officials told the AP the worst strike took place in Hillah, a southern city hit by two car bombings that killed eight people.
The Iraqi cities of Diwaniyah, Basra, Kut, Samarra, Madain and Mahmoudiyah were also attacked, said the AP.
A total of 11 bombs were set off by remote control, according to Reuters.
It was not immediately clear who was behind the attacks, which add to rising violence in Iraq.
Over 6,000 people have been reported killed there in the past year.