Seven car bombs in central Iraq -- three in Baghdad and four to its south -- killed 13 people on Tuesday, officials said, after another series of blasts the day before.
Iraqi authorities have so far failed to curb a year-long surge in violence plaguing the country, despite carrying out wide-ranging operations against militants.
Bayaa in south Baghdad was hit by two car bombs which killed five people, while another exploded in a nearby area, killing two.
At least 20 people were injured in the blasts.
And three more car bombs exploded in Hilla, south of Baghdad, killing five people and wounding 22, while another in Mussayib killed one and wounded 23.
The attacks followed four car bombs in Baghdad on Monday that killed at least 16 people.
Violence in Iraq has reached a level not seen since 2008, when it was emerging from a brutal period of sectarian killings that claimed tens of thousands of lives.
And all of one major city and parts of another in Anbar province, west of Baghdad, have been held by anti-government fighters for weeks.
Attacks and clashes have killed more than 470 people so far this month and over 1,450 since the start of the year, according to AFP figures based on security and medical sources.