The apparently co-ordinated blasts come just a day after Prime Minister Ibrahim Jaafari unveiled his new cabinet.
No-one has admitted carrying out the attacks, the deadliest of which took place in Baghdad’s Adhamiya area.
A tape purportedly from al-Qaeda’s leader in Iraq, Abu Musab al-Zarqawi, calls for more attacks on US forces.
Posted on a website, the taped message is delivered by a speaker identifying himself as the Jordanian militant. He vows not to let President George W Bush enjoy “peace of mind”.