Reports quoting medical and security officials say that the bombs were placed in three vehicles which exploded within minutes of each other in a largely Shi'ite neighborhood of the city.
There was no immediate claim of responsibility for the attack.
Also today, the U.S. military said six U.S. troops have been killed in Iraq.
Three of the soldiers were killed on December 25, and three more were killed today in roadside-bomb attacks near Baghdad.
The Associated Press reports that the fatalities raise the U.S. military death toll in Iraq to at least 2,978 -- five more than the number of people believed killed in the September 11, 2001, terrorist attacks in the United States.
(AFP, AP, Reuters)