It was not immediately clear who had carried out the attacks, which appeared coordinated, but Sunni Islamist militants, including an Al Qaeda-affiliate, have been regaining momentum in their insurgency against the Shi'ite-led government.
The deadliest blast took place in Baghdad's northern Talbiya neighbourhood, where a car bomb in a busy street killed nine people.
More than two years of civil war in neighbouring Syria have aggravated deep-rooted sectarian divisions in Iraq, fraying an uneasy coalition of Shi'ite, Sunni and ethic Kurdish factions.
About 800 Iraqis were killed in August, according to the United Nations, with more than a third of the deadly attacks in Baghdad.
The bloodshed, 18 months after US troops withdrew from Iraq, has stirred concerns about a relapse towards the sectarian slaughter of 2006-07.
© Thomson Reuters 2013